HDFS-8979. Clean up checkstyle warnings in hadoop-hdfs-client module. Contributed by Mingliang Liu.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/fs/CacheFlag.java

@@ -34,7 +34,7 @@ public enum CacheFlag {
   FORCE((short) 0x01);
   private final short mode;
 
-  private CacheFlag(short mode) {
+  CacheFlag(short mode) {
     this.mode = mode;
   }
 

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/fs/HdfsBlockLocation.java

@@ -17,8 +17,6 @@
  */
 package org.apache.hadoop.fs;
 
-import java.io.IOException;
-
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
@@ -34,8 +32,7 @@ public class HdfsBlockLocation extends BlockLocation {
 
   private final LocatedBlock block;
 
-  public HdfsBlockLocation(BlockLocation loc, LocatedBlock block) 
+  public HdfsBlockLocation(BlockLocation loc, LocatedBlock block) {
-      throws IOException {
     // Initialize with data from passed in BlockLocation
     super(loc);
     this.block = block;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/fs/XAttr.java

@@ -57,12 +57,12 @@ import org.apache.hadoop.classification.InterfaceAudience;
 @InterfaceAudience.Private
 public class XAttr {
 
-  public static enum NameSpace {
+  public enum NameSpace {
     USER,
     TRUSTED,
     SECURITY,
     SYSTEM,
-    RAW;
+    RAW
   }
 
   private final NameSpace ns;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/BlockMissingException.java

@@ -24,8 +24,8 @@ import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 
 /**
-  * This exception is thrown when a read encounters a block that has no locations
+  * This exception is thrown when a read encounters a block that has no
-  * associated with it.
+  * locations associated with it.
   */
 @InterfaceAudience.Private
 @InterfaceStability.Evolving
@@ -41,7 +41,8 @@ public class BlockMissingException extends IOException {
    * @param filename name of corrupted file
    * @param description a description of the corruption details
    */
-  public BlockMissingException(String filename, String description, long offset) {
+  public BlockMissingException(String filename, String description,
+      long offset) {
     super(description);
     this.filename = filename;
     this.offset = offset;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/BlockReader.java

@@ -32,7 +32,6 @@ import org.apache.hadoop.hdfs.shortcircuit.ClientMmap;
 @InterfaceAudience.Private
 public interface BlockReader extends ByteBufferReadable {
 
-
   /* same interface as inputStream java.io.InputStream#read()
    * used by DFSInputStream#read()
    * This violates one rule when there is a checksum error:
@@ -55,7 +54,7 @@ public interface BlockReader extends ByteBufferReadable {
    * network I/O.
    * This may return more than what is actually present in the block.
    */
-  int available() throws IOException;
+  int available();
 
   /**
    * Close the block reader.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/BlockReaderFactory.java

@@ -170,7 +170,8 @@ public class BlockReaderFactory implements ShortCircuitReplicaCreator {
   private RemotePeerFactory remotePeerFactory;
 
   /**
-   * UserGroupInformation  to use for legacy block reader local objects, if needed.
+   * UserGroupInformation to use for legacy block reader local objects,
+   * if needed.
    */
   private UserGroupInformation userGroupInformation;
 
@@ -426,9 +427,9 @@ public class BlockReaderFactory implements ShortCircuitReplicaCreator {
       return null;
     }
     if (clientContext.getDisableLegacyBlockReaderLocal()) {
-        PerformanceAdvisory.LOG.debug("{}: can't construct " +
+      PerformanceAdvisory.LOG.debug("{}: can't construct " +
-            "BlockReaderLocalLegacy because " +
+          "BlockReaderLocalLegacy because " +
-            "disableLegacyBlockReaderLocal is set.", this);
+          "disableLegacyBlockReaderLocal is set.", this);
       return null;
     }
     IOException ioe;
@@ -470,7 +471,8 @@ public class BlockReaderFactory implements ShortCircuitReplicaCreator {
       return null;
     }
     ShortCircuitCache cache = clientContext.getShortCircuitCache();
-    ExtendedBlockId key = new ExtendedBlockId(block.getBlockId(), block.getBlockPoolId());
+    ExtendedBlockId key = new ExtendedBlockId(block.getBlockId(),
+        block.getBlockPoolId());
     ShortCircuitReplicaInfo info = cache.fetchOrCreate(key, this);
     InvalidToken exc = info.getInvalidTokenException();
     if (exc != null) {
@@ -501,14 +503,15 @@ public class BlockReaderFactory implements ShortCircuitReplicaCreator {
    *
    * @return    Null if we could not communicate with the datanode,
    *            a new ShortCircuitReplicaInfo object otherwise.
-   *            ShortCircuitReplicaInfo objects may contain either an InvalidToken
+   *            ShortCircuitReplicaInfo objects may contain either an
-   *            exception, or a ShortCircuitReplica object ready to use.
+   *            InvalidToken exception, or a ShortCircuitReplica object ready to
+   *            use.
    */
   @Override
   public ShortCircuitReplicaInfo createShortCircuitReplicaInfo() {
     if (createShortCircuitReplicaInfoCallback != null) {
       ShortCircuitReplicaInfo info =
-        createShortCircuitReplicaInfoCallback.createShortCircuitReplicaInfo();
+          createShortCircuitReplicaInfoCallback.createShortCircuitReplicaInfo();
       if (info != null) return info;
     }
     LOG.trace("{}: trying to create ShortCircuitReplicaInfo.", this);
@@ -682,7 +685,7 @@ public class BlockReaderFactory implements ShortCircuitReplicaCreator {
         }
         if (curPeer.fromCache) {
           // Handle an I/O error we got when using a cached peer.  These are
-          // considered less serious, because the underlying socket may be stale.
+          // considered less serious because the underlying socket may be stale.
           LOG.debug("Closed potentially stale domain peer {}", peer, ioe);
         } else {
           // Handle an I/O error we got when using a newly created domain peer.
@@ -800,7 +803,7 @@ public class BlockReaderFactory implements ShortCircuitReplicaCreator {
     }
     try {
       Peer peer = remotePeerFactory.newConnectedPeer(inetSocketAddress, token,
-        datanode);
+          datanode);
       LOG.trace("nextTcpPeer: created newConnectedPeer {}", peer);
       return new BlockReaderPeer(peer, false);
     } catch (IOException e) {

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/BlockReaderLocal.java

@@ -335,9 +335,8 @@ class BlockReaderLocal implements BlockReader {
    */
   private synchronized int fillBuffer(ByteBuffer buf, boolean canSkipChecksum)
       throws IOException {
-    TraceScope scope = tracer.newScope(
+    try (TraceScope ignored = tracer.newScope(
-        "BlockReaderLocal#fillBuffer(" + block.getBlockId() + ")");
+        "BlockReaderLocal#fillBuffer(" + block.getBlockId() + ")")) {
-    try {
       int total = 0;
       long startDataPos = dataPos;
       int startBufPos = buf.position();
@@ -358,7 +357,8 @@ class BlockReaderLocal implements BlockReader {
           buf.limit(buf.position());
           buf.position(startBufPos);
           createChecksumBufIfNeeded();
-          int checksumsNeeded = (total + bytesPerChecksum - 1) / bytesPerChecksum;
+          int checksumsNeeded = (total + bytesPerChecksum - 1) /
+              bytesPerChecksum;
           checksumBuf.clear();
           checksumBuf.limit(checksumsNeeded * checksumSize);
           long checksumPos = BlockMetadataHeader.getHeaderSize()
@@ -367,8 +367,8 @@ class BlockReaderLocal implements BlockReader {
             int nRead = checksumIn.read(checksumBuf, checksumPos);
             if (nRead < 0) {
               throw new IOException("Got unexpected checksum file EOF at " +
-                  checksumPos + ", block file position " + startDataPos + " for " +
+                  checksumPos + ", block file position " + startDataPos +
-                  "block " + block + " of file " + filename);
+                  " for block " + block + " of file " + filename);
             }
             checksumPos += nRead;
           }
@@ -380,24 +380,16 @@ class BlockReaderLocal implements BlockReader {
         }
       }
       return total;
-    } finally {
-      scope.close();
     }
   }
 
   private boolean createNoChecksumContext() {
-    if (verifyChecksum) {
+    return !verifyChecksum ||
-      if (storageType != null && storageType.isTransient()) {
+        // Checksums are not stored for replicas on transient storage.  We do
-        // Checksums are not stored for replicas on transient storage.  We do not
+        // not anchor, because we do not intend for client activity to block
-        // anchor, because we do not intend for client activity to block eviction
+        // eviction from transient storage on the DataNode side.
-        // from transient storage on the DataNode side.
+        (storageType != null && storageType.isTransient()) ||
-        return true;
+        replica.addNoChecksumAnchor();
-      } else {
-        return replica.addNoChecksumAnchor();
-      }
-    } else {
-      return true;
-    }
   }
 
   private void releaseNoChecksumContext() {
@@ -473,11 +465,11 @@ class BlockReaderLocal implements BlockReader {
     dataBuf.limit(maxReadaheadLength);
     if (canSkipChecksum) {
       dataBuf.position(slop);
-      fillBuffer(dataBuf, canSkipChecksum);
+      fillBuffer(dataBuf, true);
     } else {
       dataPos -= slop;
       dataBuf.position(0);
-      fillBuffer(dataBuf, canSkipChecksum);
+      fillBuffer(dataBuf, false);
     }
     dataBuf.limit(dataBuf.position());
     dataBuf.position(Math.min(dataBuf.position(), slop));
@@ -621,7 +613,7 @@ class BlockReaderLocal implements BlockReader {
   }
 
   @Override
-  public int available() throws IOException {
+  public int available() {
     // We never do network I/O in BlockReaderLocal.
     return Integer.MAX_VALUE;
   }
@@ -677,7 +669,7 @@ class BlockReaderLocal implements BlockReader {
   @Override
   public ClientMmap getClientMmap(EnumSet<ReadOption> opts) {
     boolean anchor = verifyChecksum &&
-        (opts.contains(ReadOption.SKIP_CHECKSUMS) == false);
+        !opts.contains(ReadOption.SKIP_CHECKSUMS);
     if (anchor) {
       if (!createNoChecksumContext()) {
         LOG.trace("can't get an mmap for {} of {} since SKIP_CHECKSUMS was not "

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/BlockReaderLocalLegacy.java

@@ -56,10 +56,10 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * BlockReaderLocalLegacy enables local short circuited reads. If the DFS client is on
+ * BlockReaderLocalLegacy enables local short circuited reads. If the DFS client
- * the same machine as the datanode, then the client can read files directly
+ * is on the same machine as the datanode, then the client can read files
- * from the local file system rather than going through the datanode for better
+ * directly from the local file system rather than going through the datanode
- * performance. <br>
+ * for better performance. <br>
  *
  * This is the legacy implementation based on HDFS-2246, which requires
  * permissions on the datanode to be set so that clients can directly access the
@@ -90,7 +90,8 @@ class BlockReaderLocalLegacy implements BlockReader {
     LocalDatanodeInfo() {
       final int cacheSize = 10000;
       final float hashTableLoadFactor = 0.75f;
-      int hashTableCapacity = (int) Math.ceil(cacheSize / hashTableLoadFactor) + 1;
+      int hashTableCapacity = (int) Math.ceil(cacheSize / hashTableLoadFactor)
+          + 1;
       cache = Collections
           .synchronizedMap(new LinkedHashMap<ExtendedBlock, BlockLocalPathInfo>(
               hashTableCapacity, hashTableLoadFactor, true) {
@@ -135,7 +136,8 @@ class BlockReaderLocalLegacy implements BlockReader {
       return cache.get(b);
     }
 
-    private void setBlockLocalPathInfo(ExtendedBlock b, BlockLocalPathInfo info) {
+    private void setBlockLocalPathInfo(ExtendedBlock b,
+        BlockLocalPathInfo info) {
       cache.put(b, info);
     }
 
@@ -146,7 +148,8 @@ class BlockReaderLocalLegacy implements BlockReader {
 
   // Multiple datanodes could be running on the local machine. Store proxies in
   // a map keyed by the ipc port of the datanode.
-  private static final Map<Integer, LocalDatanodeInfo> localDatanodeInfoMap = new HashMap<Integer, LocalDatanodeInfo>();
+  private static final Map<Integer, LocalDatanodeInfo> localDatanodeInfoMap =
+      new HashMap<>();
 
   private final FileInputStream dataIn; // reader for the data file
   private final FileInputStream checksumIn;   // reader for the checksum file
@@ -234,12 +237,12 @@ class BlockReaderLocalLegacy implements BlockReader {
             new DataInputStream(checksumIn), blk);
         long firstChunkOffset = startOffset
             - (startOffset % checksum.getBytesPerChecksum());
-        localBlockReader = new BlockReaderLocalLegacy(scConf, file, blk, token,
+        localBlockReader = new BlockReaderLocalLegacy(scConf, file, blk,
-            startOffset, length, pathinfo, checksum, true, dataIn,
+            startOffset, checksum, true, dataIn, firstChunkOffset, checksumIn,
-            firstChunkOffset, checksumIn, tracer);
+            tracer);
       } else {
-        localBlockReader = new BlockReaderLocalLegacy(scConf, file, blk, token,
+        localBlockReader = new BlockReaderLocalLegacy(scConf, file, blk,
-            startOffset, length, pathinfo, dataIn, tracer);
+            startOffset, dataIn, tracer);
       }
     } catch (IOException e) {
       // remove from cache
@@ -274,14 +277,15 @@ class BlockReaderLocalLegacy implements BlockReader {
       ExtendedBlock blk, DatanodeInfo node, Configuration conf, int timeout,
       Token<BlockTokenIdentifier> token, boolean connectToDnViaHostname,
       StorageType storageType) throws IOException {
-    LocalDatanodeInfo localDatanodeInfo = getLocalDatanodeInfo(node.getIpcPort());
+    LocalDatanodeInfo localDatanodeInfo =
-    BlockLocalPathInfo pathinfo = null;
+        getLocalDatanodeInfo(node.getIpcPort());
+    BlockLocalPathInfo pathinfo;
     ClientDatanodeProtocol proxy = localDatanodeInfo.getDatanodeProxy(ugi, node,
         conf, timeout, connectToDnViaHostname);
     try {
       // make RPC to local datanode to find local pathnames of blocks
       pathinfo = proxy.getBlockLocalPathInfo(blk, token);
-      // We cannot cache the path information for a replica on transient storage.
+      // We can't cache the path information for a replica on transient storage.
       // If the replica gets evicted, then it moves to a different path.  Then,
       // our next attempt to read from the cached path would fail to find the
       // file.  Additionally, the failure would cause us to disable legacy
@@ -315,17 +319,15 @@ class BlockReaderLocalLegacy implements BlockReader {
   }
 
   private BlockReaderLocalLegacy(ShortCircuitConf conf, String hdfsfile,
-      ExtendedBlock block, Token<BlockTokenIdentifier> token, long startOffset,
+      ExtendedBlock block, long startOffset, FileInputStream dataIn,
-      long length, BlockLocalPathInfo pathinfo, FileInputStream dataIn,
       Tracer tracer) throws IOException {
-    this(conf, hdfsfile, block, token, startOffset, length, pathinfo,
+    this(conf, hdfsfile, block, startOffset,
         DataChecksum.newDataChecksum(DataChecksum.Type.NULL, 4), false,
         dataIn, startOffset, null, tracer);
   }
 
   private BlockReaderLocalLegacy(ShortCircuitConf conf, String hdfsfile,
-      ExtendedBlock block, Token<BlockTokenIdentifier> token, long startOffset,
+      ExtendedBlock block, long startOffset, DataChecksum checksum,
-      long length, BlockLocalPathInfo pathinfo, DataChecksum checksum,
       boolean verifyChecksum, FileInputStream dataIn, long firstChunkOffset,
       FileInputStream checksumIn, Tracer tracer) throws IOException {
     this.filename = hdfsfile;
@@ -343,17 +345,20 @@ class BlockReaderLocalLegacy implements BlockReader {
 
     final int chunksPerChecksumRead = getSlowReadBufferNumChunks(
         conf.getShortCircuitBufferSize(), bytesPerChecksum);
-    slowReadBuff = bufferPool.getBuffer(bytesPerChecksum * chunksPerChecksumRead);
+    slowReadBuff = bufferPool.getBuffer(
+        bytesPerChecksum * chunksPerChecksumRead);
     checksumBuff = bufferPool.getBuffer(checksumSize * chunksPerChecksumRead);
     // Initially the buffers have nothing to read.
     slowReadBuff.flip();
     checksumBuff.flip();
     boolean success = false;
     try {
-      // Skip both input streams to beginning of the chunk containing startOffset
+      // Skip both input streams to beginning of the chunk containing
+      // startOffset
       IOUtils.skipFully(dataIn, firstChunkOffset);
       if (checksumIn != null) {
-        long checkSumOffset = (firstChunkOffset / bytesPerChecksum) * checksumSize;
+        long checkSumOffset = (firstChunkOffset / bytesPerChecksum) *
+            checksumSize;
         IOUtils.skipFully(checksumIn, checkSumOffset);
       }
       success = true;
@@ -371,9 +376,8 @@ class BlockReaderLocalLegacy implements BlockReader {
    */
   private int fillBuffer(FileInputStream stream, ByteBuffer buf)
       throws IOException {
-    TraceScope scope = tracer.
+    try (TraceScope ignored = tracer.
-        newScope("BlockReaderLocalLegacy#fillBuffer(" + blockId + ")");
+        newScope("BlockReaderLocalLegacy#fillBuffer(" + blockId + ")")) {
-    try {
       int bytesRead = stream.getChannel().read(buf);
       if (bytesRead < 0) {
         //EOF
@@ -388,8 +392,6 @@ class BlockReaderLocalLegacy implements BlockReader {
         bytesRead += n;
       }
       return bytesRead;
-    } finally {
-      scope.close();
     }
   }
 
@@ -426,7 +428,8 @@ class BlockReaderLocalLegacy implements BlockReader {
       if (slowReadBuff.hasRemaining()) {
         // There are remaining bytes from a small read available. This usually
         // means this read is unaligned, which falls back to the slow path.
-        int fromSlowReadBuff = Math.min(buf.remaining(), slowReadBuff.remaining());
+        int fromSlowReadBuff = Math.min(buf.remaining(),
+            slowReadBuff.remaining());
         writeSlice(slowReadBuff, buf, fromSlowReadBuff);
         nRead += fromSlowReadBuff;
       }
@@ -458,8 +461,10 @@ class BlockReaderLocalLegacy implements BlockReader {
 
       // offsetFromChunkBoundary > 0 => unaligned read, use slow path to read
       // until chunk boundary
-      if ((buf.remaining() > 0 && buf.remaining() < bytesPerChecksum) || offsetFromChunkBoundary > 0) {
+      if ((buf.remaining() > 0 && buf.remaining() < bytesPerChecksum) ||
-        int toRead = Math.min(buf.remaining(), bytesPerChecksum - offsetFromChunkBoundary);
+          offsetFromChunkBoundary > 0) {
+        int toRead = Math.min(buf.remaining(),
+            bytesPerChecksum - offsetFromChunkBoundary);
         int readResult = fillSlowReadBuffer(toRead);
         if (readResult == -1) {
           return nRead;
@@ -470,7 +475,8 @@ class BlockReaderLocalLegacy implements BlockReader {
         }
       }
     } else {
-      // Non-checksummed reads are much easier; we can just fill the buffer directly.
+      // Non-checksummed reads are much easier; we can just fill the buffer
+      // directly.
       nRead = doByteBufferRead(buf);
       if (nRead > 0) {
         buf.position(buf.position() + nRead);
@@ -512,7 +518,7 @@ class BlockReaderLocalLegacy implements BlockReader {
     if (verifyChecksum) {
       assert buf.remaining() % bytesPerChecksum == 0;
     }
-    int dataRead = -1;
+    int dataRead;
 
     int oldpos = buf.position();
     // Read as much as we can into the buffer.
@@ -528,9 +534,10 @@ class BlockReaderLocalLegacy implements BlockReader {
       toChecksum.limit(oldpos + dataRead);
 
       checksumBuff.clear();
-      // Equivalent to (int)Math.ceil(toChecksum.remaining() * 1.0 / bytesPerChecksum );
+      // Equivalent to
+      // (int)Math.ceil(toChecksum.remaining() * 1.0 / bytesPerChecksum );
       int numChunks =
-        (toChecksum.remaining() + bytesPerChecksum - 1) / bytesPerChecksum;
+          (toChecksum.remaining() + bytesPerChecksum - 1) / bytesPerChecksum;
       checksumBuff.limit(checksumSize * numChunks);
 
       fillBuffer(checksumIn, checksumBuff);
@@ -571,7 +578,7 @@ class BlockReaderLocalLegacy implements BlockReader {
    * @return the number of bytes available to read, or -1 if EOF.
    */
   private synchronized int fillSlowReadBuffer(int len) throws IOException {
-    int nRead = -1;
+    int nRead;
     if (slowReadBuff.hasRemaining()) {
       // Already got data, good to go.
       nRead = Math.min(len, slowReadBuff.remaining());
@@ -579,7 +586,8 @@ class BlockReaderLocalLegacy implements BlockReader {
       // Round a complete read of len bytes (plus any implicit offset) to the
       // next chunk boundary, since we try and read in multiples of a chunk
       int nextChunk = len + offsetFromChunkBoundary +
-          (bytesPerChecksum - ((len + offsetFromChunkBoundary) % bytesPerChecksum));
+          (bytesPerChecksum -
+              ((len + offsetFromChunkBoundary) % bytesPerChecksum));
       int limit = Math.min(nextChunk, slowReadBuff.capacity());
       assert limit % bytesPerChecksum == 0;
 
@@ -598,7 +606,8 @@ class BlockReaderLocalLegacy implements BlockReader {
   }
 
   @Override
-  public synchronized int read(byte[] buf, int off, int len) throws IOException {
+  public synchronized int read(byte[] buf, int off, int len)
+      throws IOException {
     LOG.trace("read off {} len {}", off, len);
     if (!verifyChecksum) {
       return dataIn.read(buf, off, len);
@@ -708,7 +717,7 @@ class BlockReaderLocalLegacy implements BlockReader {
   }
 
   @Override
-  public int available() throws IOException {
+  public int available() {
     // We never do network I/O in BlockReaderLocalLegacy.
     return Integer.MAX_VALUE;
   }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/ClientContext.java

@@ -41,13 +41,13 @@ import org.slf4j.LoggerFactory;
  */
 @InterfaceAudience.Private
 public class ClientContext {
-  private static final Logger LOG = LoggerFactory.getLogger(ClientContext.class);
+  private static final Logger LOG = LoggerFactory.getLogger(
+      ClientContext.class);
 
   /**
    * Global map of context names to caches contexts.
    */
-  private final static HashMap<String, ClientContext> CACHES =
+  private final static HashMap<String, ClientContext> CACHES = new HashMap<>();
-      new HashMap<String, ClientContext>();
 
   /**
    * Name of context.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSInotifyEventInputStream.java

@@ -69,8 +69,8 @@ public class DFSInotifyEventInputStream {
     this(namenode, tracer, namenode.getCurrentEditLogTxid());
   }
 
-  DFSInotifyEventInputStream(ClientProtocol namenode,
+  DFSInotifyEventInputStream(ClientProtocol namenode, Tracer tracer,
-        Tracer tracer, long lastReadTxid) throws IOException {
+      long lastReadTxid) {
     this.namenode = namenode;
     this.it = Iterators.emptyIterator();
     this.lastReadTxid = lastReadTxid;
@@ -94,8 +94,7 @@ public class DFSInotifyEventInputStream {
    * The next available batch of events will be returned.
    */
   public EventBatch poll() throws IOException, MissingEventsException {
-    TraceScope scope = tracer.newScope("inotifyPoll");
+    try (TraceScope ignored = tracer.newScope("inotifyPoll")) {
-    try {
       // need to keep retrying until the NN sends us the latest committed txid
       if (lastReadTxid == -1) {
         LOG.debug("poll(): lastReadTxid is -1, reading current txid from NN");
@@ -119,7 +118,7 @@ public class DFSInotifyEventInputStream {
           }
         } else {
           LOG.debug("poll(): read no edits from the NN when requesting edits " +
-            "after txid {}", lastReadTxid);
+              "after txid {}", lastReadTxid);
           return null;
         }
       }
@@ -130,8 +129,6 @@ public class DFSInotifyEventInputStream {
       } else {
         return null;
       }
-    } finally {
-      scope.close();
     }
   }
 
@@ -175,9 +172,8 @@ public class DFSInotifyEventInputStream {
    */
   public EventBatch poll(long time, TimeUnit tu) throws IOException,
       InterruptedException, MissingEventsException {
-    TraceScope scope = tracer.newScope("inotifyPollWithTimeout");
+    EventBatch next;
-    EventBatch next = null;
+    try (TraceScope ignored = tracer.newScope("inotifyPollWithTimeout")) {
-    try {
       long initialTime = Time.monotonicNow();
       long totalWait = TimeUnit.MILLISECONDS.convert(time, tu);
       long nextWait = INITIAL_WAIT_MS;
@@ -195,8 +191,6 @@ public class DFSInotifyEventInputStream {
             nextWait);
         Thread.sleep(nextWait);
       }
-    } finally {
-      scope.close();
     }
     return next;
   }
@@ -212,9 +206,8 @@ public class DFSInotifyEventInputStream {
    */
   public EventBatch take() throws IOException, InterruptedException,
       MissingEventsException {
-    TraceScope scope = tracer.newScope("inotifyTake");
+    EventBatch next;
-    EventBatch next = null;
+    try (TraceScope ignored = tracer.newScope("inotifyTake")) {
-    try {
       int nextWaitMin = INITIAL_WAIT_MS;
       while ((next = poll()) == null) {
         // sleep for a random period between nextWaitMin and nextWaitMin * 2
@@ -225,8 +218,6 @@ public class DFSInotifyEventInputStream {
         // the maximum sleep is 2 minutes
         nextWaitMin = Math.min(60000, nextWaitMin * 2);
       }
-    } finally {
-      scope.close();
     }
 
     return next;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSInputStream.java

@@ -55,11 +55,9 @@ import org.apache.hadoop.fs.CanUnbuffer;
 import org.apache.hadoop.fs.ChecksumException;
 import org.apache.hadoop.fs.FSInputStream;
 import org.apache.hadoop.fs.FileEncryptionInfo;
-import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.HasEnhancedByteBufferAccess;
 import org.apache.hadoop.fs.ReadOption;
 import org.apache.hadoop.fs.StorageType;
-import org.apache.hadoop.fs.UnresolvedLinkException;
 import org.apache.hadoop.hdfs.client.impl.DfsClientConf;
 import org.apache.hadoop.hdfs.protocol.ClientDatanodeProtocol;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
@@ -85,13 +83,15 @@ import org.apache.htrace.core.Tracer;
 
 import com.google.common.annotations.VisibleForTesting;
 
+import javax.annotation.Nonnull;
+
 /****************************************************************
  * DFSInputStream provides bytes from a named file.  It handles
  * negotiation of the namenode and various datanodes as necessary.
  ****************************************************************/
 @InterfaceAudience.Private
 public class DFSInputStream extends FSInputStream
-implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
+    implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
     HasEnhancedByteBufferAccess, CanUnbuffer {
   @VisibleForTesting
   public static boolean tcpReadsDisabledForTesting = false;
@@ -137,7 +137,7 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
   private synchronized IdentityHashStore<ByteBuffer, Object>
         getExtendedReadBuffers() {
     if (extendedReadBuffers == null) {
-      extendedReadBuffers = new IdentityHashStore<ByteBuffer, Object>(0);
+      extendedReadBuffers = new IdentityHashStore<>(0);
     }
     return extendedReadBuffers;
   }
@@ -246,7 +246,7 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
   /* XXX Use of CocurrentHashMap is temp fix. Need to fix
    * parallel accesses to DFSInputStream (through ptreads) properly */
   private final ConcurrentHashMap<DatanodeInfo, DatanodeInfo> deadNodes =
-             new ConcurrentHashMap<DatanodeInfo, DatanodeInfo>();
+             new ConcurrentHashMap<>();
 
   private byte[] oneByteBuf; // used for 'int read()'
 
@@ -255,7 +255,7 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
   }
 
   DFSInputStream(DFSClient dfsClient, String src, boolean verifyChecksum,
-      LocatedBlocks locatedBlocks) throws IOException, UnresolvedLinkException {
+      LocatedBlocks locatedBlocks) throws IOException {
     this.dfsClient = dfsClient;
     this.verifyChecksum = verifyChecksum;
     this.src = src;
@@ -270,8 +270,7 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
    * Grab the open-file info from namenode
    * @param refreshLocatedBlocks whether to re-fetch locatedblocks
    */
-  void openInfo(boolean refreshLocatedBlocks) throws IOException,
+  void openInfo(boolean refreshLocatedBlocks) throws IOException {
-      UnresolvedLinkException {
     final DfsClientConf conf = dfsClient.getConf();
     synchronized(infoLock) {
       lastBlockBeingWrittenLength =
@@ -375,8 +374,8 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
       }
       catch(IOException ioe) {
         if (ioe instanceof RemoteException &&
-          (((RemoteException) ioe).unwrapRemoteException() instanceof
+            (((RemoteException) ioe).unwrapRemoteException() instanceof
-            ReplicaNotFoundException)) {
+                ReplicaNotFoundException)) {
           // special case : replica might not be on the DN, treat as 0 length
           replicaNotFoundCount--;
         }
@@ -526,12 +525,12 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
         blocks = getFinalizedBlockRange(offset,
           Math.min(length, lengthOfCompleteBlk - offset));
       } else {
-        blocks = new ArrayList<LocatedBlock>(1);
+        blocks = new ArrayList<>(1);
       }
 
       // get the blocks from incomplete block range
       if (readLengthPastCompleteBlk) {
-         blocks.add(locatedBlocks.getLastLocatedBlock());
+        blocks.add(locatedBlocks.getLastLocatedBlock());
       }
 
       return blocks;
@@ -547,7 +546,7 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
       long offset, long length) throws IOException {
     synchronized(infoLock) {
       assert (locatedBlocks != null) : "locatedBlocks is null";
-      List<LocatedBlock> blockRange = new ArrayList<LocatedBlock>();
+      List<LocatedBlock> blockRange = new ArrayList<>();
       // search cached blocks first
       int blockIdx = locatedBlocks.findBlock(offset);
       if (blockIdx < 0) { // block is not cached
@@ -591,7 +590,7 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
     //
     // Connect to best DataNode for desired Block, with potential offset
     //
-    DatanodeInfo chosenNode = null;
+    DatanodeInfo chosenNode;
     int refetchToken = 1; // only need to get a new access token once
     int refetchEncryptionKey = 1; // only need to get a new encryption key once
 
@@ -639,7 +638,7 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
         } else {
           connectFailedOnce = true;
           DFSClient.LOG.warn("Failed to connect to " + targetAddr + " for block"
-            + ", add to deadNodes and continue. " + ex, ex);
+              + ", add to deadNodes and continue. " + ex, ex);
           // Put chosen node into dead list, continue
           addToDeadNodes(chosenNode);
         }
@@ -722,8 +721,8 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
    * strategy-agnostic.
    */
   interface ReaderStrategy {
-    public int doRead(BlockReader blockReader, int off, int len)
+    int doRead(BlockReader blockReader, int off, int len)
-        throws ChecksumException, IOException;
+        throws IOException;
 
     /**
      * Copy data from the src ByteBuffer into the read buffer.
@@ -733,7 +732,7 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
      * @param length Useful only when the ReadStrategy is based on a byte array.
      *               Indicate the length of the data to copy.
      */
-    public int copyFrom(ByteBuffer src, int offset, int length);
+    int copyFrom(ByteBuffer src, int offset, int length);
   }
 
   protected void updateReadStatistics(ReadStatistics readStatistics,
@@ -762,7 +761,7 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
 
     @Override
     public int doRead(BlockReader blockReader, int off, int len)
-          throws ChecksumException, IOException {
+        throws IOException {
       int nRead = blockReader.read(buf, off, len);
       updateReadStatistics(readStatistics, nRead, blockReader);
       return nRead;
@@ -787,7 +786,7 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
 
     @Override
     public int doRead(BlockReader blockReader, int off, int len)
-        throws ChecksumException, IOException {
+        throws IOException {
       int oldpos = buf.position();
       int oldlimit = buf.limit();
       boolean success = false;
@@ -856,7 +855,7 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
         }
         ioe = e;
       }
-      boolean sourceFound = false;
+      boolean sourceFound;
       if (retryCurrentNode) {
         /* possibly retry the same node so that transient errors don't
          * result in application level failures (e.g. Datanode could have
@@ -879,8 +878,7 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
     if (closed.get()) {
       throw new IOException("Stream closed");
     }
-    Map<ExtendedBlock,Set<DatanodeInfo>> corruptedBlockMap 
+    Map<ExtendedBlock,Set<DatanodeInfo>> corruptedBlockMap = new HashMap<>();
-      = new HashMap<ExtendedBlock, Set<DatanodeInfo>>();
     failures = 0;
     if (pos < getFileLength()) {
       int retries = 2;
@@ -936,26 +934,21 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
    * Read the entire buffer.
    */
   @Override
-  public synchronized int read(final byte buf[], int off, int len) throws IOException {
+  public synchronized int read(@Nonnull final byte buf[], int off, int len)
+      throws IOException {
     ReaderStrategy byteArrayReader = new ByteArrayStrategy(buf);
-    TraceScope scope =
+    try (TraceScope ignored =
-        dfsClient.newPathTraceScope("DFSInputStream#byteArrayRead", src);
+             dfsClient.newPathTraceScope("DFSInputStream#byteArrayRead", src)) {
-    try {
       return readWithStrategy(byteArrayReader, off, len);
-    } finally {
-      scope.close();
     }
   }
 
   @Override
   public synchronized int read(final ByteBuffer buf) throws IOException {
     ReaderStrategy byteBufferReader = new ByteBufferStrategy(buf);
-    TraceScope scope =
+    try (TraceScope ignored =
-        dfsClient.newPathTraceScope("DFSInputStream#byteBufferRead", src);
+             dfsClient.newPathTraceScope("DFSInputStream#byteBufferRead", src)){
-    try {
       return readWithStrategy(byteBufferReader, 0, buf.remaining());
-    } finally {
-      scope.close();
     }
   }
 
@@ -965,11 +958,11 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
    */
   protected void addIntoCorruptedBlockMap(ExtendedBlock blk, DatanodeInfo node,
       Map<ExtendedBlock, Set<DatanodeInfo>> corruptedBlockMap) {
-    Set<DatanodeInfo> dnSet = null;
+    Set<DatanodeInfo> dnSet;
     if((corruptedBlockMap.containsKey(blk))) {
       dnSet = corruptedBlockMap.get(blk);
     }else {
-      dnSet = new HashSet<DatanodeInfo>();
+      dnSet = new HashSet<>();
     }
     if (!dnSet.contains(node)) {
       dnSet.add(node);
@@ -985,7 +978,7 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
         return result;
       } else {
         String errMsg = getBestNodeDNAddrPairErrorString(block.getLocations(),
-          deadNodes, ignoredNodes);
+            deadNodes, ignoredNodes);
         String blockInfo = block.getBlock() + " file=" + src;
         if (failures >= dfsClient.getConf().getMaxBlockAcquireFailures()) {
           String description = "Could not obtain block: " + blockInfo;
@@ -1019,7 +1012,7 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
               ThreadLocalRandom.current().nextDouble();
           DFSClient.LOG.warn("DFS chooseDataNode: got # " + (failures + 1) + " IOException, will wait for " + waitTime + " msec.");
           Thread.sleep((long)waitTime);
-        } catch (InterruptedException iex) {
+        } catch (InterruptedException ignored) {
         }
         deadNodes.clear(); //2nd option is to remove only nodes[blockId]
         openInfo(true);
@@ -1122,14 +1115,11 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
       public ByteBuffer call() throws Exception {
         byte[] buf = bb.array();
         int offset = bb.position();
-        TraceScope scope = dfsClient.getTracer().
+        try (TraceScope ignored = dfsClient.getTracer().
-            newScope("hedgedRead" + hedgedReadId, parentSpanId);
+            newScope("hedgedRead" + hedgedReadId, parentSpanId)) {
-        try {
           actualGetFromOneDataNode(datanode, block, start, end, buf,
               offset, corruptedBlockMap);
           return bb;
-        } finally {
-          scope.close();
         }
       }
     };
@@ -1271,12 +1261,11 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
       Map<ExtendedBlock, Set<DatanodeInfo>> corruptedBlockMap)
       throws IOException {
     final DfsClientConf conf = dfsClient.getConf();
-    ArrayList<Future<ByteBuffer>> futures = new ArrayList<Future<ByteBuffer>>();
+    ArrayList<Future<ByteBuffer>> futures = new ArrayList<>();
     CompletionService<ByteBuffer> hedgedService =
-        new ExecutorCompletionService<ByteBuffer>(
+        new ExecutorCompletionService<>(dfsClient.getHedgedReadsThreadPool());
-        dfsClient.getHedgedReadsThreadPool());
+    ArrayList<DatanodeInfo> ignored = new ArrayList<>();
-    ArrayList<DatanodeInfo> ignored = new ArrayList<DatanodeInfo>();
+    ByteBuffer bb;
-    ByteBuffer bb = null;
     int len = (int) (end - start + 1);
     int hedgedReadId = 0;
     block = refreshLocatedBlock(block);
@@ -1308,11 +1297,9 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
           // Ignore this node on next go around.
           ignored.add(chosenNode.info);
           dfsClient.getHedgedReadMetrics().incHedgedReadOps();
-          continue; // no need to refresh block locations
+          // continue; no need to refresh block locations
-        } catch (InterruptedException e) {
+        } catch (InterruptedException | ExecutionException e) {
           // Ignore
-        } catch (ExecutionException e) {
-          // Ignore already logged in the call.
         }
       } else {
         // We are starting up a 'hedged' read. We have a read already
@@ -1377,10 +1364,7 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
       ByteBuffer bb = future.get();
       futures.remove(future);
       return bb;
-    } catch (ExecutionException e) {
+    } catch (ExecutionException | CancellationException e) {
-      // already logged in the Callable
-      futures.remove(future);
-    } catch (CancellationException ce) {
       // already logged in the Callable
       futures.remove(future);
     }
@@ -1440,12 +1424,9 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
   @Override
   public int read(long position, byte[] buffer, int offset, int length)
       throws IOException {
-    TraceScope scope = dfsClient.
+    try (TraceScope ignored = dfsClient.
-        newPathTraceScope("DFSInputStream#byteArrayPread", src);
+        newPathTraceScope("DFSInputStream#byteArrayPread", src)) {
-    try {
       return pread(position, buffer, offset, length);
-    } finally {
-      scope.close();
     }
   }
 
@@ -1470,8 +1451,7 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
     // corresponding to position and realLen
     List<LocatedBlock> blockRange = getBlockRange(position, realLen);
     int remaining = realLen;
-    Map<ExtendedBlock,Set<DatanodeInfo>> corruptedBlockMap 
+    Map<ExtendedBlock,Set<DatanodeInfo>> corruptedBlockMap = new HashMap<>();
-      = new HashMap<ExtendedBlock, Set<DatanodeInfo>>();
     for (LocatedBlock blk : blockRange) {
       long targetStart = position - blk.getStartOffset();
       long bytesToRead = Math.min(remaining, blk.getBlockSize() - targetStart);
@@ -1748,7 +1728,7 @@ implements ByteBufferReadable, CanSetDropBehind, CanSetReadahead,
    * zero-copy read.
    */
   private static final ByteBuffer EMPTY_BUFFER =
-    ByteBuffer.allocateDirect(0).asReadOnlyBuffer();
+      ByteBuffer.allocateDirect(0).asReadOnlyBuffer();
 
   @Override
   public synchronized ByteBuffer read(ByteBufferPool bufferPool,

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSOutputStream.java

@@ -32,7 +32,6 @@ import org.apache.hadoop.fs.CreateFlag;
 import org.apache.hadoop.fs.FSOutputSummer;
 import org.apache.hadoop.fs.FileAlreadyExistsException;
 import org.apache.hadoop.fs.FileEncryptionInfo;
-import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.ParentNotDirectoryException;
 import org.apache.hadoop.fs.Syncable;
 import org.apache.hadoop.fs.permission.FsPermission;
@@ -121,8 +120,9 @@ public class DFSOutputStream extends FSOutputSummer
   private FileEncryptionInfo fileEncryptionInfo;
 
   /** Use {@link ByteArrayManager} to create buffer for non-heartbeat packets.*/
-  protected DFSPacket createPacket(int packetSize, int chunksPerPkt, long offsetInBlock,
+  protected DFSPacket createPacket(int packetSize, int chunksPerPkt,
-      long seqno, boolean lastPacketInBlock) throws InterruptedIOException {
+      long offsetInBlock, long seqno, boolean lastPacketInBlock)
+      throws InterruptedIOException {
     final byte[] buf;
     final int bufferSize = PacketHeader.PKT_MAX_HEADER_LEN + packetSize;
 
@@ -159,9 +159,7 @@ public class DFSOutputStream extends FSOutputSummer
       return null;
     }
     DatanodeInfo[] value = new DatanodeInfo[currentNodes.length];
-    for (int i = 0; i < currentNodes.length; i++) {
+    System.arraycopy(currentNodes, 0, value, 0, currentNodes.length);
-      value[i] = currentNodes[i];
-    }
     return value;
   }
 
@@ -179,8 +177,8 @@ public class DFSOutputStream extends FSOutputSummer
     return checksum;
   }
 
-  private DFSOutputStream(DFSClient dfsClient, String src, Progressable progress,
+  private DFSOutputStream(DFSClient dfsClient, String src,
-      HdfsFileStatus stat, DataChecksum checksum) throws IOException {
+      Progressable progress, HdfsFileStatus stat, DataChecksum checksum) {
     super(getChecksum4Compute(checksum, stat));
     this.dfsClient = dfsClient;
     this.src = src;
@@ -188,7 +186,7 @@ public class DFSOutputStream extends FSOutputSummer
     this.blockSize = stat.getBlockSize();
     this.blockReplication = stat.getReplication();
     this.fileEncryptionInfo = stat.getFileEncryptionInfo();
-    this.cachingStrategy = new AtomicReference<CachingStrategy>(
+    this.cachingStrategy = new AtomicReference<>(
         dfsClient.getDefaultWriteCachingStrategy());
     if (progress != null) {
       DFSClient.LOG.debug("Set non-null progress callback on DFSOutputStream "
@@ -202,8 +200,9 @@ public class DFSOutputStream extends FSOutputSummer
     }
     if (blockSize % bytesPerChecksum != 0) {
       throw new HadoopIllegalArgumentException("Invalid values: "
-          + HdfsClientConfigKeys.DFS_BYTES_PER_CHECKSUM_KEY + " (=" + bytesPerChecksum
+          + HdfsClientConfigKeys.DFS_BYTES_PER_CHECKSUM_KEY
-          + ") must divide block size (=" + blockSize + ").");
+          + " (=" + bytesPerChecksum + ") must divide block size (=" +
+          blockSize + ").");
     }
     this.byteArrayManager = dfsClient.getClientContext().getByteArrayManager();
   }
@@ -215,7 +214,8 @@ public class DFSOutputStream extends FSOutputSummer
     this(dfsClient, src, progress, stat, checksum);
     this.shouldSyncBlock = flag.contains(CreateFlag.SYNC_BLOCK);
 
-    computePacketChunkSize(dfsClient.getConf().getWritePacketSize(), bytesPerChecksum);
+    computePacketChunkSize(dfsClient.getConf().getWritePacketSize(),
+        bytesPerChecksum);
 
     streamer = new DataStreamer(stat, null, dfsClient, src, progress, checksum,
         cachingStrategy, byteArrayManager, favoredNodes);
@@ -223,11 +223,10 @@ public class DFSOutputStream extends FSOutputSummer
 
   static DFSOutputStream newStreamForCreate(DFSClient dfsClient, String src,
       FsPermission masked, EnumSet<CreateFlag> flag, boolean createParent,
-      short replication, long blockSize, Progressable progress, int buffersize,
+      short replication, long blockSize, Progressable progress,
       DataChecksum checksum, String[] favoredNodes) throws IOException {
-    TraceScope scope =
+    try (TraceScope ignored =
-        dfsClient.newPathTraceScope("newStreamForCreate", src);
+             dfsClient.newPathTraceScope("newStreamForCreate", src)) {
-    try {
       HdfsFileStatus stat = null;
 
       // Retry the create if we get a RetryStartFileException up to a maximum
@@ -238,7 +237,7 @@ public class DFSOutputStream extends FSOutputSummer
         shouldRetry = false;
         try {
           stat = dfsClient.namenode.create(src, masked, dfsClient.clientName,
-              new EnumSetWritable<CreateFlag>(flag), createParent, replication,
+              new EnumSetWritable<>(flag), createParent, replication,
               blockSize, SUPPORTED_CRYPTO_VERSIONS);
           break;
         } catch (RemoteException re) {
@@ -273,8 +272,6 @@ public class DFSOutputStream extends FSOutputSummer
           flag, progress, checksum, favoredNodes);
       out.start();
       return out;
-    } finally {
-      scope.close();
     }
   }
 
@@ -294,17 +291,17 @@ public class DFSOutputStream extends FSOutputSummer
     // The last partial block of the file has to be filled.
     if (!toNewBlock && lastBlock != null) {
       // indicate that we are appending to an existing block
-      streamer = new DataStreamer(lastBlock, stat, dfsClient, src, progress, checksum,
+      streamer = new DataStreamer(lastBlock, stat, dfsClient, src, progress,
-          cachingStrategy, byteArrayManager);
+          checksum, cachingStrategy, byteArrayManager);
       getStreamer().setBytesCurBlock(lastBlock.getBlockSize());
       adjustPacketChunkSize(stat);
       getStreamer().setPipelineInConstruction(lastBlock);
     } else {
       computePacketChunkSize(dfsClient.getConf().getWritePacketSize(),
           bytesPerChecksum);
-      streamer = new DataStreamer(stat, lastBlock != null ? lastBlock.getBlock() : null,
+      streamer = new DataStreamer(stat,
-          dfsClient, src, progress, checksum, cachingStrategy, byteArrayManager,
+          lastBlock != null ? lastBlock.getBlock() : null, dfsClient, src,
-          favoredNodes);
+          progress, checksum, cachingStrategy, byteArrayManager, favoredNodes);
     }
   }
 
@@ -345,18 +342,15 @@ public class DFSOutputStream extends FSOutputSummer
   }
 
   static DFSOutputStream newStreamForAppend(DFSClient dfsClient, String src,
-      EnumSet<CreateFlag> flags, int bufferSize, Progressable progress,
+      EnumSet<CreateFlag> flags, Progressable progress, LocatedBlock lastBlock,
-      LocatedBlock lastBlock, HdfsFileStatus stat, DataChecksum checksum,
+      HdfsFileStatus stat, DataChecksum checksum, String[] favoredNodes)
-      String[] favoredNodes) throws IOException {
+      throws IOException {
-    TraceScope scope =
+    try (TraceScope ignored =
-        dfsClient.newPathTraceScope("newStreamForAppend", src);
+             dfsClient.newPathTraceScope("newStreamForAppend", src)) {
-    try {
       final DFSOutputStream out = new DFSOutputStream(dfsClient, src, flags,
           progress, lastBlock, stat, checksum, favoredNodes);
       out.start();
       return out;
-    } finally {
-      scope.close();
     }
   }
 
@@ -486,23 +480,15 @@ public class DFSOutputStream extends FSOutputSummer
    */
   @Override
   public void hflush() throws IOException {
-    TraceScope scope =
+    try (TraceScope ignored = dfsClient.newPathTraceScope("hflush", src)) {
-        dfsClient.newPathTraceScope("hflush", src);
-    try {
       flushOrSync(false, EnumSet.noneOf(SyncFlag.class));
-    } finally {
-      scope.close();
     }
   }
 
   @Override
   public void hsync() throws IOException {
-    TraceScope scope =
+    try (TraceScope ignored = dfsClient.newPathTraceScope("hsync", src)) {
-        dfsClient.newPathTraceScope("hsync", src);
-    try {
       flushOrSync(true, EnumSet.noneOf(SyncFlag.class));
-    } finally {
-      scope.close();
     }
   }
   
@@ -520,12 +506,8 @@ public class DFSOutputStream extends FSOutputSummer
    *          whether or not to update the block length in NameNode.
    */
   public void hsync(EnumSet<SyncFlag> syncFlags) throws IOException {
-    TraceScope scope =
+    try (TraceScope ignored = dfsClient.newPathTraceScope("hsync", src)) {
-        dfsClient.newPathTraceScope("hsync", src);
-    try {
       flushOrSync(true, syncFlags);
-    } finally {
-      scope.close();
     }
   }
 
@@ -630,13 +612,14 @@ public class DFSOutputStream extends FSOutputSummer
           dfsClient.namenode.fsync(src, fileId, dfsClient.clientName,
               lastBlockLength);
         } catch (IOException ioe) {
-          DFSClient.LOG.warn("Unable to persist blocks in hflush for " + src, ioe);
+          DFSClient.LOG.warn("Unable to persist blocks in hflush for " + src,
-          // If we got an error here, it might be because some other thread called
+              ioe);
-          // close before our hflush completed. In that case, we should throw an
+          // If we got an error here, it might be because some other thread
-          // exception that the stream is closed.
+          // called close before our hflush completed. In that case, we should
+          // throw an exception that the stream is closed.
           checkClosed();
-          // If we aren't closed but failed to sync, we should expose that to the
+          // If we aren't closed but failed to sync, we should expose that to
-          // caller.
+          // the caller.
           throw ioe;
         }
       }
@@ -647,9 +630,9 @@ public class DFSOutputStream extends FSOutputSummer
         }
       }
     } catch (InterruptedIOException interrupt) {
-      // This kind of error doesn't mean that the stream itself is broken - just the
+      // This kind of error doesn't mean that the stream itself is broken - just
-      // flushing thread got interrupted. So, we shouldn't close down the writer,
+      // the flushing thread got interrupted. So, we shouldn't close down the
-      // but instead just propagate the error
+      // writer, but instead just propagate the error
       throw interrupt;
     } catch (IOException e) {
       DFSClient.LOG.warn("Error while syncing", e);
@@ -723,7 +706,7 @@ public class DFSOutputStream extends FSOutputSummer
       return;
     }
     getStreamer().getLastException().set(new IOException("Lease timeout of "
-        + (dfsClient.getConf().getHdfsTimeout()/1000) + " seconds expired."));
+        + (dfsClient.getConf().getHdfsTimeout() / 1000) + " seconds expired."));
     closeThreads(true);
     dfsClient.endFileLease(fileId);
   }
@@ -758,12 +741,9 @@ public class DFSOutputStream extends FSOutputSummer
    */
   @Override
   public synchronized void close() throws IOException {
-    TraceScope scope =
+    try (TraceScope ignored =
-        dfsClient.newPathTraceScope("DFSOutputStream#close", src);
+             dfsClient.newPathTraceScope("DFSOutputStream#close", src)) {
-    try {
       closeImpl();
-    } finally {
-      scope.close();
     }
   }
 
@@ -788,14 +768,12 @@ public class DFSOutputStream extends FSOutputSummer
       // get last block before destroying the streamer
       ExtendedBlock lastBlock = getStreamer().getBlock();
       closeThreads(false);
-      TraceScope scope = dfsClient.getTracer().newScope("completeFile");
+      try (TraceScope ignored =
-      try {
+               dfsClient.getTracer().newScope("completeFile")) {
         completeFile(lastBlock);
-      } finally {
-        scope.close();
       }
       dfsClient.endFileLease(fileId);
-    } catch (ClosedChannelException e) {
+    } catch (ClosedChannelException ignored) {
     } finally {
       setClosed();
     }
@@ -817,12 +795,11 @@ public class DFSOutputStream extends FSOutputSummer
         if (!dfsClient.clientRunning
             || (hdfsTimeout > 0
                 && localstart + hdfsTimeout < Time.monotonicNow())) {
-            String msg = "Unable to close file because dfsclient " +
+          String msg = "Unable to close file because dfsclient " +
-                          " was unable to contact the HDFS servers." +
+              " was unable to contact the HDFS servers. clientRunning " +
-                          " clientRunning " + dfsClient.clientRunning +
+              dfsClient.clientRunning + " hdfsTimeout " + hdfsTimeout;
-                          " hdfsTimeout " + hdfsTimeout;
+          DFSClient.LOG.info(msg);
-            DFSClient.LOG.info(msg);
+          throw new IOException(msg);
-            throw new IOException(msg);
         }
         try {
           if (retries == 0) {

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSPacket.java

@@ -139,7 +139,6 @@ class DFSPacket {
   /**
    * Write the full packet, including the header, to the given output stream.
    *
-   * @param stm
    * @throws IOException
    */
   synchronized void writeTo(DataOutputStream stm) throws IOException {
@@ -173,15 +172,18 @@ class DFSPacket {
 
     // corrupt the data for testing.
     if (DFSClientFaultInjector.get().corruptPacket()) {
-      buf[headerStart+header.getSerializedSize() + checksumLen + dataLen-1] ^= 0xff;
+      buf[headerStart+header.getSerializedSize() + checksumLen + dataLen-1] ^=
+          0xff;
     }
 
     // Write the now contiguous full packet to the output stream.
-    stm.write(buf, headerStart, header.getSerializedSize() + checksumLen + dataLen);
+    stm.write(buf, headerStart,
+        header.getSerializedSize() + checksumLen + dataLen);
 
     // undo corruption.
     if (DFSClientFaultInjector.get().uncorruptPacket()) {
-      buf[headerStart+header.getSerializedSize() + checksumLen + dataLen-1] ^= 0xff;
+      buf[headerStart+header.getSerializedSize() + checksumLen + dataLen-1] ^=
+          0xff;
     }
   }
 
@@ -193,8 +195,6 @@ class DFSPacket {
 
   /**
    * Release the buffer in this packet to ByteArrayManager.
-   *
-   * @param bam
    */
   synchronized void releaseBuffer(ByteArrayManager bam) {
     bam.release(buf);

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSUtilClient.java

@@ -303,8 +303,8 @@ public class DFSUtilClient {
    * @param keys Set of keys to look for in the order of preference
    * @return a map(nameserviceId to map(namenodeId to InetSocketAddress))
    */
-  static Map<String, Map<String, InetSocketAddress>>
+  static Map<String, Map<String, InetSocketAddress>> getAddresses(
-    getAddresses(Configuration conf, String defaultAddress, String... keys) {
+      Configuration conf, String defaultAddress, String... keys) {
     Collection<String> nameserviceIds = getNameServiceIds(conf);
     return getAddressesForNsIds(conf, nameserviceIds, defaultAddress, keys);
   }
@@ -317,8 +317,7 @@ public class DFSUtilClient {
    *
    * @return a map(nameserviceId to map(namenodeId to InetSocketAddress))
    */
-  static Map<String, Map<String, InetSocketAddress>>
+  static Map<String, Map<String, InetSocketAddress>> getAddressesForNsIds(
-    getAddressesForNsIds(
       Configuration conf, Collection<String> nsIds, String defaultAddress,
       String... keys) {
     // Look for configurations of the form <key>[.<nameserviceId>][.<namenodeId>]
@@ -326,7 +325,7 @@ public class DFSUtilClient {
     Map<String, Map<String, InetSocketAddress>> ret = Maps.newLinkedHashMap();
     for (String nsId : emptyAsSingletonNull(nsIds)) {
       Map<String, InetSocketAddress> isas =
-        getAddressesForNameserviceId(conf, nsId, defaultAddress, keys);
+          getAddressesForNameserviceId(conf, nsId, defaultAddress, keys);
       if (!isas.isEmpty()) {
         ret.put(nsId, isas);
       }
@@ -533,7 +532,7 @@ public class DFSUtilClient {
 
   public static Peer peerFromSocket(Socket socket)
       throws IOException {
-    Peer peer = null;
+    Peer peer;
     boolean success = false;
     try {
       // TCP_NODELAY is crucial here because of bad interactions between
@@ -560,7 +559,7 @@ public class DFSUtilClient {
       return peer;
     } finally {
       if (!success) {
-        if (peer != null) peer.close();
+        // peer is always null so no need to call peer.close().
         socket.close();
       }
     }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DataStreamer.java

@@ -41,7 +41,6 @@ import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicReference;
 
 import org.apache.hadoop.classification.InterfaceAudience;
-import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.StorageType;
 import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys.BlockWrite;
 import org.apache.hadoop.hdfs.client.impl.DfsClientConf;
@@ -80,7 +79,6 @@ import org.apache.hadoop.util.Daemon;
 import org.apache.hadoop.util.DataChecksum;
 import org.apache.hadoop.util.Progressable;
 import org.apache.hadoop.util.Time;
-import org.apache.htrace.core.Sampler;
 import org.apache.htrace.core.Span;
 import org.apache.htrace.core.SpanId;
 import org.apache.htrace.core.TraceScope;
@@ -95,6 +93,8 @@ import com.google.common.cache.RemovalNotification;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import javax.annotation.Nonnull;
+
 /*********************************************************************
  *
  * The DataStreamer class is responsible for sending data packets to the
@@ -136,7 +136,8 @@ class DataStreamer extends Daemon {
     final InetSocketAddress isa = NetUtils.createSocketAddr(dnAddr);
     final Socket sock = client.socketFactory.createSocket();
     final int timeout = client.getDatanodeReadTimeout(length);
-    NetUtils.connect(sock, isa, client.getRandomLocalInterfaceAddr(), conf.getSocketTimeout());
+    NetUtils.connect(sock, isa, client.getRandomLocalInterfaceAddr(),
+        conf.getSocketTimeout());
     sock.setSoTimeout(timeout);
     sock.setSendBufferSize(HdfsConstants.DEFAULT_DATA_SOCKET_SIZE);
     LOG.debug("Send buf size {}", sock.getSendBufferSize());
@@ -427,7 +428,6 @@ class DataStreamer extends Daemon {
    * Construct a data streamer for appending to the last partial block
    * @param lastBlock last block of the file to be appended
    * @param stat status of the file to be appended
-   * @throws IOException if error occurs
    */
   DataStreamer(LocatedBlock lastBlock, HdfsFileStatus stat, DFSClient dfsClient,
                String src, Progressable progress, DataChecksum checksum,
@@ -620,9 +620,8 @@ class DataStreamer extends Daemon {
         LOG.debug("DataStreamer block {} sending packet {}", block, one);
 
         // write out data to remote datanode
-        TraceScope writeScope = dfsClient.getTracer().
+        try (TraceScope ignored = dfsClient.getTracer().
-            newScope("DataStreamer#writeTo", spanId);
+            newScope("DataStreamer#writeTo", spanId)) {
-        try {
           one.writeTo(blockStream);
           blockStream.flush();
         } catch (IOException e) {
@@ -634,8 +633,6 @@ class DataStreamer extends Daemon {
           // will be taken out then.
           errorState.markFirstNodeIfNotMarked();
           throw e;
-        } finally {
-          writeScope.close();
         }
         lastPacket = Time.monotonicNow();
 
@@ -725,9 +722,8 @@ class DataStreamer extends Daemon {
    * @throws IOException
    */
   void waitForAckedSeqno(long seqno) throws IOException {
-    TraceScope scope = dfsClient.getTracer().
+    try (TraceScope ignored = dfsClient.getTracer().
-        newScope("waitForAckedSeqno");
+        newScope("waitForAckedSeqno")) {
-    try {
       LOG.debug("Waiting for ack for: {}", seqno);
       long begin = Time.monotonicNow();
       try {
@@ -747,15 +743,13 @@ class DataStreamer extends Daemon {
           }
         }
         checkClosed();
-      } catch (ClosedChannelException e) {
+      } catch (ClosedChannelException cce) {
       }
       long duration = Time.monotonicNow() - begin;
       if (duration > dfsclientSlowLogThresholdMs) {
         LOG.warn("Slow waitForAckedSeqno took " + duration
             + "ms (threshold=" + dfsclientSlowLogThresholdMs + "ms)");
       }
-    } finally {
-      scope.close();
     }
   }
 
@@ -802,7 +796,7 @@ class DataStreamer extends Daemon {
         }
         checkClosed();
         queuePacket(packet);
-      } catch (ClosedChannelException e) {
+      } catch (ClosedChannelException ignored) {
       }
     }
   }
@@ -901,10 +895,7 @@ class DataStreamer extends Daemon {
       assert false;
     }
 
-    if (addr != null && NetUtils.isLocalAddress(addr)) {
+    return addr != null && NetUtils.isLocalAddress(addr);
-      return true;
-    }
-    return false;
   }
 
   //
@@ -1137,17 +1128,15 @@ class DataStreamer extends Daemon {
   ) throws IOException {
     if (nodes.length != original.length + 1) {
       throw new IOException(
-          new StringBuilder()
+          "Failed to replace a bad datanode on the existing pipeline "
-              .append("Failed to replace a bad datanode on the existing pipeline ")
+              + "due to no more good datanodes being available to try. "
-              .append("due to no more good datanodes being available to try. ")
+              + "(Nodes: current=" + Arrays.asList(nodes)
-              .append("(Nodes: current=").append(Arrays.asList(nodes))
+              + ", original=" + Arrays.asList(original) + "). "
-              .append(", original=").append(Arrays.asList(original)).append("). ")
+              + "The current failed datanode replacement policy is "
-              .append("The current failed datanode replacement policy is ")
+              + dfsClient.dtpReplaceDatanodeOnFailure
-              .append(dfsClient.dtpReplaceDatanodeOnFailure).append(", and ")
+              + ", and a client may configure this via '"
-              .append("a client may configure this via '")
+              + BlockWrite.ReplaceDatanodeOnFailure.POLICY_KEY
-              .append(BlockWrite.ReplaceDatanodeOnFailure.POLICY_KEY)
+              + "' in its configuration.");
-              .append("' in its configuration.")
-              .toString());
     }
     for(int i = 0; i < nodes.length; i++) {
       int j = 0;
@@ -1196,7 +1185,7 @@ class DataStreamer extends Daemon {
     final StorageType[] originalTypes = storageTypes;
     final String[] originalIDs = storageIDs;
     IOException caughtException = null;
-    ArrayList<DatanodeInfo> exclude = new ArrayList<DatanodeInfo>(failed);
+    ArrayList<DatanodeInfo> exclude = new ArrayList<>(failed);
     while (tried < 3) {
       LocatedBlock lb;
       //get a new datanode
@@ -1235,7 +1224,8 @@ class DataStreamer extends Daemon {
 
   private void transfer(final DatanodeInfo src, final DatanodeInfo[] targets,
                         final StorageType[] targetStorageTypes,
-                        final Token<BlockTokenIdentifier> blockToken) throws IOException {
+                        final Token<BlockTokenIdentifier> blockToken)
+      throws IOException {
     //transfer replica to the new datanode
     Socket sock = null;
     DataOutputStream out = null;
@@ -1246,7 +1236,8 @@ class DataStreamer extends Daemon {
 
       // transfer timeout multiplier based on the transfer size
       // One per 200 packets = 12.8MB. Minimum is 2.
-      int multi = 2 + (int)(bytesSent/dfsClient.getConf().getWritePacketSize())/200;
+      int multi = 2 + (int)(bytesSent /dfsClient.getConf().getWritePacketSize())
+          / 200;
       final long readTimeout = dfsClient.getDatanodeReadTimeout(multi);
 
       OutputStream unbufOut = NetUtils.getOutputStream(sock, writeTimeout);
@@ -1413,13 +1404,14 @@ class DataStreamer extends Daemon {
         // good reports should follow bad ones, if client committed
         // with those nodes.
         Thread.sleep(2000);
-      } catch (InterruptedException ie) {}
+      } catch (InterruptedException ignored) {
+      }
     }
   }
 
-  LocatedBlock updateBlockForPipeline() throws IOException {
+  private LocatedBlock updateBlockForPipeline() throws IOException {
-    return dfsClient.namenode.updateBlockForPipeline(
+    return dfsClient.namenode.updateBlockForPipeline(block,
-        block, dfsClient.clientName);
+        dfsClient.clientName);
   }
 
   /** update pipeline at the namenode */
@@ -1437,12 +1429,12 @@ class DataStreamer extends Daemon {
    * Must get block ID and the IDs of the destinations from the namenode.
    * Returns the list of target datanodes.
    */
-  private LocatedBlock nextBlockOutputStream() throws IOException {
+  protected LocatedBlock nextBlockOutputStream() throws IOException {
-    LocatedBlock lb = null;
+    LocatedBlock lb;
-    DatanodeInfo[] nodes = null;
+    DatanodeInfo[] nodes;
-    StorageType[] storageTypes = null;
+    StorageType[] storageTypes;
     int count = dfsClient.getConf().getNumBlockWriteRetry();
-    boolean success = false;
+    boolean success;
     ExtendedBlock oldBlock = block;
     do {
       errorState.reset();
@@ -1493,7 +1485,6 @@ class DataStreamer extends Daemon {
       LOG.info("nodes are empty for write pipeline of " + block);
       return false;
     }
-    Status pipelineStatus = SUCCESS;
     String firstBadLink = "";
     boolean checkRestart = false;
     if (LOG.isDebugEnabled()) {
@@ -1528,25 +1519,26 @@ class DataStreamer extends Daemon {
         // Xmit header info to datanode
         //
 
-        BlockConstructionStage bcs = recoveryFlag? stage.getRecoveryStage(): stage;
+        BlockConstructionStage bcs = recoveryFlag ?
+            stage.getRecoveryStage() : stage;
 
         // We cannot change the block length in 'block' as it counts the number
         // of bytes ack'ed.
         ExtendedBlock blockCopy = new ExtendedBlock(block);
         blockCopy.setNumBytes(stat.getBlockSize());
 
-        boolean[] targetPinnings = getPinnings(nodes, true);
+        boolean[] targetPinnings = getPinnings(nodes);
         // send the request
         new Sender(out).writeBlock(blockCopy, nodeStorageTypes[0], accessToken,
             dfsClient.clientName, nodes, nodeStorageTypes, null, bcs,
             nodes.length, block.getNumBytes(), bytesSent, newGS,
             checksum4WriteBlock, cachingStrategy.get(), isLazyPersistFile,
-            (targetPinnings == null ? false : targetPinnings[0]), targetPinnings);
+            (targetPinnings != null && targetPinnings[0]), targetPinnings);
 
         // receive ack for connect
         BlockOpResponseProto resp = BlockOpResponseProto.parseFrom(
             PBHelperClient.vintPrefixed(blockReplyStream));
-        pipelineStatus = resp.getStatus();
+        Status pipelineStatus = resp.getStatus();
         firstBadLink = resp.getFirstBadLink();
 
         // Got an restart OOB ack.
@@ -1571,7 +1563,8 @@ class DataStreamer extends Daemon {
         if (!errorState.isRestartingNode()) {
           LOG.info("Exception in createBlockOutputStream", ie);
         }
-        if (ie instanceof InvalidEncryptionKeyException && refetchEncryptionKey > 0) {
+        if (ie instanceof InvalidEncryptionKeyException &&
+            refetchEncryptionKey > 0) {
           LOG.info("Will fetch a new encryption key and retry, "
               + "encryption key was invalid when connecting to "
               + nodes[0] + " : " + ie);
@@ -1593,14 +1586,15 @@ class DataStreamer extends Daemon {
             }
           }
         } else {
-          assert checkRestart == false;
+          assert !checkRestart;
           errorState.setBadNodeIndex(0);
         }
 
         final int i = errorState.getBadNodeIndex();
         // Check whether there is a restart worth waiting for.
         if (checkRestart && shouldWaitForRestart(i)) {
-          errorState.initRestartingNode(i, "Datanode " + i + " is restarting: " + nodes[i]);
+          errorState.initRestartingNode(i, "Datanode " + i + " is restarting: "
+              + nodes[i]);
         }
         errorState.setError(true);
         lastException.set(ie);
@@ -1610,7 +1604,6 @@ class DataStreamer extends Daemon {
           IOUtils.closeSocket(s);
           s = null;
           IOUtils.closeStream(out);
-          out = null;
           IOUtils.closeStream(blockReplyStream);
           blockReplyStream = null;
         }
@@ -1619,19 +1612,18 @@ class DataStreamer extends Daemon {
     }
   }
 
-  private boolean[] getPinnings(DatanodeInfo[] nodes, boolean shouldLog) {
+  private boolean[] getPinnings(DatanodeInfo[] nodes) {
     if (favoredNodes == null) {
       return null;
     } else {
       boolean[] pinnings = new boolean[nodes.length];
-      HashSet<String> favoredSet =
+      HashSet<String> favoredSet = new HashSet<>(Arrays.asList(favoredNodes));
-          new HashSet<String>(Arrays.asList(favoredNodes));
       for (int i = 0; i < nodes.length; i++) {
         pinnings[i] = favoredSet.remove(nodes[i].getXferAddrWithHostname());
         LOG.debug("{} was chosen by name node (favored={}).",
             nodes[i].getXferAddrWithHostname(), pinnings[i]);
       }
-      if (shouldLog && !favoredSet.isEmpty()) {
+      if (!favoredSet.isEmpty()) {
         // There is one or more favored nodes that were not allocated.
         LOG.warn("These favored nodes were specified but not chosen: "
             + favoredSet + " Specified favored nodes: "
@@ -1777,7 +1769,7 @@ class DataStreamer extends Daemon {
    * For heartbeat packets, create buffer directly by new byte[]
    * since heartbeats should not be blocked.
    */
-  private DFSPacket createHeartbeatPacket() throws InterruptedIOException {
+  private DFSPacket createHeartbeatPacket() {
     final byte[] buf = new byte[PacketHeader.PKT_MAX_HEADER_LEN];
     return new DFSPacket(buf, 0, 0, DFSPacket.HEART_BEAT_SEQNO, 0, false);
   }
@@ -1789,7 +1781,8 @@ class DataStreamer extends Daemon {
         .removalListener(new RemovalListener<DatanodeInfo, DatanodeInfo>() {
           @Override
           public void onRemoval(
-              RemovalNotification<DatanodeInfo, DatanodeInfo> notification) {
+              @Nonnull RemovalNotification<DatanodeInfo, DatanodeInfo>
+                  notification) {
             LOG.info("Removing node " + notification.getKey()
                 + " from the excluded nodes list");
           }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java

@@ -41,7 +41,6 @@ import org.apache.hadoop.fs.CreateFlag;
 import org.apache.hadoop.fs.FSDataInputStream;
 import org.apache.hadoop.fs.FSDataOutputStream;
 import org.apache.hadoop.fs.FSLinkResolver;
-import org.apache.hadoop.fs.FileAlreadyExistsException;
 import org.apache.hadoop.fs.FileChecksum;
 import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.FileSystem;
@@ -52,7 +51,6 @@ import org.apache.hadoop.fs.LocatedFileStatus;
 import org.apache.hadoop.fs.Options;
 import org.apache.hadoop.fs.XAttrSetFlag;
 import org.apache.hadoop.fs.Options.ChecksumOpt;
-import org.apache.hadoop.fs.ParentNotDirectoryException;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.PathFilter;
 import org.apache.hadoop.fs.RemoteIterator;
@@ -88,7 +86,6 @@ import org.apache.hadoop.hdfs.security.token.block.InvalidBlockTokenException;
 import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.net.NetUtils;
-import org.apache.hadoop.security.AccessControlException;
 import org.apache.hadoop.security.Credentials;
 import org.apache.hadoop.security.token.Token;
 import org.apache.hadoop.util.Progressable;
@@ -174,7 +171,7 @@ public class DistributedFileSystem extends FileSystem {
     String result = fixRelativePart(dir).toUri().getPath();
     if (!DFSUtilClient.isValidName(result)) {
       throw new IllegalArgumentException("Invalid DFS directory name " +
-                                         result);
+          result);
     }
     workingDir = fixRelativePart(dir);
   }
@@ -198,7 +195,7 @@ public class DistributedFileSystem extends FileSystem {
     String result = file.toUri().getPath();
     if (!DFSUtilClient.isValidName(result)) {
       throw new IllegalArgumentException("Pathname " + result + " from " +
-                                         file+" is not a valid DFS filename.");
+          file+" is not a valid DFS filename.");
     }
     return result;
   }
@@ -282,8 +279,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(f);
     return new FileSystemLinkResolver<Boolean>() {
       @Override
-      public Boolean doCall(final Path p)
+      public Boolean doCall(final Path p) throws IOException{
-          throws IOException, UnresolvedLinkException {
         return dfs.recoverLease(getPathName(p));
       }
       @Override
@@ -306,10 +302,9 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(f);
     return new FileSystemLinkResolver<FSDataInputStream>() {
       @Override
-      public FSDataInputStream doCall(final Path p)
+      public FSDataInputStream doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         final DFSInputStream dfsis =
-          dfs.open(getPathName(p), bufferSize, verifyChecksum);
+            dfs.open(getPathName(p), bufferSize, verifyChecksum);
         return dfs.createWrappedInputStream(dfsis);
       }
       @Override
@@ -413,13 +408,12 @@ public class DistributedFileSystem extends FileSystem {
       final FsPermission permission, final boolean overwrite,
       final int bufferSize, final short replication, final long blockSize,
       final Progressable progress, final InetSocketAddress[] favoredNodes)
-          throws IOException {
+      throws IOException {
     statistics.incrementWriteOps(1);
     Path absF = fixRelativePart(f);
     return new FileSystemLinkResolver<HdfsDataOutputStream>() {
       @Override
-      public HdfsDataOutputStream doCall(final Path p)
+      public HdfsDataOutputStream doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         final DFSOutputStream out = dfs.create(getPathName(f), permission,
             overwrite ? EnumSet.of(CreateFlag.CREATE, CreateFlag.OVERWRITE)
                 : EnumSet.of(CreateFlag.CREATE),
@@ -444,18 +438,18 @@ public class DistributedFileSystem extends FileSystem {
 
   @Override
   public FSDataOutputStream create(final Path f, final FsPermission permission,
-    final EnumSet<CreateFlag> cflags, final int bufferSize,
+      final EnumSet<CreateFlag> cflags, final int bufferSize,
-    final short replication, final long blockSize, final Progressable progress,
+      final short replication, final long blockSize,
-    final ChecksumOpt checksumOpt) throws IOException {
+      final Progressable progress, final ChecksumOpt checksumOpt)
+      throws IOException {
     statistics.incrementWriteOps(1);
     Path absF = fixRelativePart(f);
     return new FileSystemLinkResolver<FSDataOutputStream>() {
       @Override
-      public FSDataOutputStream doCall(final Path p)
+      public FSDataOutputStream doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         final DFSOutputStream dfsos = dfs.create(getPathName(p), permission,
-                cflags, replication, blockSize, progress, bufferSize,
+            cflags, replication, blockSize, progress, bufferSize,
-                checksumOpt);
+            checksumOpt);
         return dfs.createWrappedOutputStream(dfsos, statistics);
       }
       @Override
@@ -469,14 +463,14 @@ public class DistributedFileSystem extends FileSystem {
 
   @Override
   protected HdfsDataOutputStream primitiveCreate(Path f,
-    FsPermission absolutePermission, EnumSet<CreateFlag> flag, int bufferSize,
+      FsPermission absolutePermission, EnumSet<CreateFlag> flag, int bufferSize,
-    short replication, long blockSize, Progressable progress,
+      short replication, long blockSize, Progressable progress,
-    ChecksumOpt checksumOpt) throws IOException {
+      ChecksumOpt checksumOpt) throws IOException {
     statistics.incrementWriteOps(1);
     final DFSOutputStream dfsos = dfs.primitiveCreate(
-      getPathName(fixRelativePart(f)),
+        getPathName(fixRelativePart(f)),
-      absolutePermission, flag, true, replication, blockSize,
+        absolutePermission, flag, true, replication, blockSize,
-      progress, bufferSize, checksumOpt);
+        progress, bufferSize, checksumOpt);
     return dfs.createWrappedOutputStream(dfsos, statistics);
   }
 
@@ -495,10 +489,9 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(f);
     return new FileSystemLinkResolver<FSDataOutputStream>() {
       @Override
-      public FSDataOutputStream doCall(final Path p) throws IOException,
+      public FSDataOutputStream doCall(final Path p) throws IOException {
-          UnresolvedLinkException {
         final DFSOutputStream dfsos = dfs.create(getPathName(p), permission,
-          flag, false, replication, blockSize, progress, bufferSize, null);
+            flag, false, replication, blockSize, progress, bufferSize, null);
         return dfs.createWrappedOutputStream(dfsos, statistics);
       }
 
@@ -512,15 +505,13 @@ public class DistributedFileSystem extends FileSystem {
   }
 
   @Override
-  public boolean setReplication(Path src, 
+  public boolean setReplication(Path src, final short replication)
-                                final short replication
+      throws IOException {
-                               ) throws IOException {
     statistics.incrementWriteOps(1);
     Path absF = fixRelativePart(src);
     return new FileSystemLinkResolver<Boolean>() {
       @Override
-      public Boolean doCall(final Path p)
+      public Boolean doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         return dfs.setReplication(getPathName(p), replication);
       }
       @Override
@@ -544,8 +535,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(src);
     new FileSystemLinkResolver<Void>() {
       @Override
-      public Void doCall(final Path p)
+      public Void doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         dfs.setStoragePolicy(getPathName(p), policyName);
         return null;
       }
@@ -571,7 +561,7 @@ public class DistributedFileSystem extends FileSystem {
 
       @Override
       public BlockStoragePolicySpi next(final FileSystem fs, final Path p)
-          throws IOException, UnresolvedLinkException {
+          throws IOException {
         return fs.getStoragePolicy(p);
       }
     }.resolve(this, absF);
@@ -585,7 +575,6 @@ public class DistributedFileSystem extends FileSystem {
 
   /**
    * Deprecated. Prefer {@link FileSystem#getAllStoragePolicies()}
-   * @return
    * @throws IOException
    */
   @Deprecated
@@ -662,8 +651,7 @@ public class DistributedFileSystem extends FileSystem {
       // Keep trying to resolve the destination
       return new FileSystemLinkResolver<Boolean>() {
         @Override
-        public Boolean doCall(final Path p)
+        public Boolean doCall(final Path p) throws IOException {
-            throws IOException, UnresolvedLinkException {
           return dfs.rename(getPathName(source), getPathName(p));
         }
         @Override
@@ -695,8 +683,7 @@ public class DistributedFileSystem extends FileSystem {
       // Keep trying to resolve the destination
       new FileSystemLinkResolver<Void>() {
         @Override
-        public Void doCall(final Path p)
+        public Void doCall(final Path p) throws IOException {
-            throws IOException, UnresolvedLinkException {
           dfs.rename(getPathName(source), getPathName(p), options);
           return null;
         }
@@ -716,8 +703,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(f);
     return new FileSystemLinkResolver<Boolean>() {
       @Override
-      public Boolean doCall(final Path p)
+      public Boolean doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         return dfs.truncate(getPathName(p), newLength);
       }
       @Override
@@ -734,8 +720,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(f);
     return new FileSystemLinkResolver<Boolean>() {
       @Override
-      public Boolean doCall(final Path p)
+      public Boolean doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         return dfs.delete(getPathName(p), recursive);
       }
       @Override
@@ -752,8 +737,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(f);
     return new FileSystemLinkResolver<ContentSummary>() {
       @Override
-      public ContentSummary doCall(final Path p)
+      public ContentSummary doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         return dfs.getContentSummary(getPathName(p));
       }
       @Override
@@ -765,15 +749,15 @@ public class DistributedFileSystem extends FileSystem {
   }
 
   /** Set a directory's quotas
-   * @see org.apache.hadoop.hdfs.protocol.ClientProtocol#setQuota(String, long, long, StorageType)
+   * @see org.apache.hadoop.hdfs.protocol.ClientProtocol#setQuota(String,
+   * long, long, StorageType)
    */
   public void setQuota(Path src, final long namespaceQuota,
       final long storagespaceQuota) throws IOException {
     Path absF = fixRelativePart(src);
     new FileSystemLinkResolver<Void>() {
       @Override
-      public Void doCall(final Path p)
+      public Void doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         dfs.setQuota(getPathName(p), namespaceQuota, storagespaceQuota);
         return null;
       }
@@ -795,22 +779,21 @@ public class DistributedFileSystem extends FileSystem {
    * @param quota value of the specific storage type quota to be modified.
    * Maybe {@link HdfsConstants#QUOTA_RESET} to clear quota by storage type.
    */
-  public void setQuotaByStorageType(
+  public void setQuotaByStorageType(Path src, final StorageType type,
-    Path src, final StorageType type, final long quota)
+      final long quota)
-    throws IOException {
+      throws IOException {
     Path absF = fixRelativePart(src);
     new FileSystemLinkResolver<Void>() {
       @Override
-      public Void doCall(final Path p)
+      public Void doCall(final Path p) throws IOException {
-        throws IOException, UnresolvedLinkException {
         dfs.setQuotaByStorageType(getPathName(p), type, quota);
         return null;
       }
       @Override
       public Void next(final FileSystem fs, final Path p)
-        throws IOException {
+          throws IOException {
-        // setQuotaByStorageType is not defined in FileSystem, so we only can resolve
+        // setQuotaByStorageType is not defined in FileSystem, so we only can
-        // within this DFS
+        // resolve within this DFS
         return doCall(p);
       }
     }.resolve(this, absF);
@@ -840,9 +823,9 @@ public class DistributedFileSystem extends FileSystem {
     // The directory size is too big that it needs to fetch more
     // estimate the total number of entries in the directory
     int totalNumEntries =
-      partialListing.length + thisListing.getRemainingEntries();
+        partialListing.length + thisListing.getRemainingEntries();
     ArrayList<FileStatus> listing =
-      new ArrayList<FileStatus>(totalNumEntries);
+        new ArrayList<>(totalNumEntries);
     // add the first batch of entries to the array list
     for (HdfsFileStatus fileStatus : partialListing) {
       listing.add(fileStatus.makeQualified(getUri(), p));
@@ -880,8 +863,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(p);
     return new FileSystemLinkResolver<FileStatus[]>() {
       @Override
-      public FileStatus[] doCall(final Path p)
+      public FileStatus[] doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         return listStatusInternal(p);
       }
       @Override
@@ -895,18 +877,18 @@ public class DistributedFileSystem extends FileSystem {
   @Override
   protected RemoteIterator<LocatedFileStatus> listLocatedStatus(final Path p,
       final PathFilter filter)
-  throws IOException {
+      throws IOException {
     Path absF = fixRelativePart(p);
     return new FileSystemLinkResolver<RemoteIterator<LocatedFileStatus>>() {
       @Override
       public RemoteIterator<LocatedFileStatus> doCall(final Path p)
-          throws IOException, UnresolvedLinkException {
+          throws IOException {
-        return new DirListingIterator<LocatedFileStatus>(p, filter, true);
+        return new DirListingIterator<>(p, filter, true);
       }
 
       @Override
-      public RemoteIterator<LocatedFileStatus> next(final FileSystem fs, final Path p)
+      public RemoteIterator<LocatedFileStatus> next(final FileSystem fs,
-          throws IOException {
+          final Path p) throws IOException {
         if (fs instanceof DistributedFileSystem) {
           return ((DistributedFileSystem)fs).listLocatedStatus(p, filter);
         }
@@ -929,19 +911,19 @@ public class DistributedFileSystem extends FileSystem {
    */
   @Override
   public RemoteIterator<FileStatus> listStatusIterator(final Path p)
-  throws IOException {
+      throws IOException {
     Path absF = fixRelativePart(p);
     return new FileSystemLinkResolver<RemoteIterator<FileStatus>>() {
       @Override
       public RemoteIterator<FileStatus> doCall(final Path p)
-          throws IOException, UnresolvedLinkException {
+          throws IOException {
-        return new DirListingIterator<FileStatus>(p, false);
+        return new DirListingIterator<>(p, false);
       }
 
       @Override
       public RemoteIterator<FileStatus> next(final FileSystem fs, final Path p)
           throws IOException {
-          return ((DistributedFileSystem)fs).listStatusIterator(p);
+        return ((DistributedFileSystem)fs).listStatusIterator(p);
       }
     }.resolve(this, absF);
 
@@ -957,7 +939,7 @@ public class DistributedFileSystem extends FileSystem {
    * @param <T> the type of the file status
    */
   private class  DirListingIterator<T extends FileStatus>
-  implements RemoteIterator<T> {
+      implements RemoteIterator<T> {
     private DirectoryListing thisListing;
     private int i;
     private Path p;
@@ -999,7 +981,7 @@ public class DistributedFileSystem extends FileSystem {
         } else {
           next = (T)fileStat.makeQualified(getUri(), p);
         }
-          // apply filter if not null
+        // apply filter if not null
         if (filter == null || filter.accept(next.getPath())) {
           curStat = next;
         }
@@ -1074,8 +1056,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(f);
     return new FileSystemLinkResolver<Boolean>() {
       @Override
-      public Boolean doCall(final Path p)
+      public Boolean doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         return dfs.mkdirs(getPathName(p), permission, createParent);
       }
 
@@ -1096,7 +1077,7 @@ public class DistributedFileSystem extends FileSystem {
   @SuppressWarnings("deprecation")
   @Override
   protected boolean primitiveMkdir(Path f, FsPermission absolutePermission)
-    throws IOException {
+      throws IOException {
     statistics.incrementWriteOps(1);
     return dfs.primitiveMkdir(getPathName(f), absolutePermission);
   }
@@ -1213,7 +1194,7 @@ public class DistributedFileSystem extends FileSystem {
 
   @Override
   public RemoteIterator<Path> listCorruptFileBlocks(Path path)
-    throws IOException {
+      throws IOException {
     return new CorruptFileBlockIterator(dfs, path);
   }
 
@@ -1223,8 +1204,8 @@ public class DistributedFileSystem extends FileSystem {
   }
 
   /** @return datanode statistics for the given type. */
-  public DatanodeInfo[] getDataNodeStats(final DatanodeReportType type
+  public DatanodeInfo[] getDataNodeStats(final DatanodeReportType type)
-      ) throws IOException {
+      throws IOException {
     return dfs.datanodeReport(type);
   }
 
@@ -1235,7 +1216,7 @@ public class DistributedFileSystem extends FileSystem {
    *    HdfsConstants.SafeModeAction,boolean)
    */
   public boolean setSafeMode(HdfsConstants.SafeModeAction action)
-  throws IOException {
+      throws IOException {
     return setSafeMode(action, false);
   }
 
@@ -1260,7 +1241,7 @@ public class DistributedFileSystem extends FileSystem {
    * 
    * @see org.apache.hadoop.hdfs.protocol.ClientProtocol#saveNamespace()
    */
-  public void saveNamespace() throws AccessControlException, IOException {
+  public void saveNamespace() throws IOException {
     dfs.saveNamespace();
   }
   
@@ -1270,7 +1251,7 @@ public class DistributedFileSystem extends FileSystem {
    * @see org.apache.hadoop.hdfs.protocol.ClientProtocol#rollEdits()
    * @return the transaction ID of the newly created segment
    */
-  public long rollEdits() throws AccessControlException, IOException {
+  public long rollEdits() throws IOException {
     return dfs.rollEdits();
   }
 
@@ -1279,8 +1260,7 @@ public class DistributedFileSystem extends FileSystem {
    *
    * @see org.apache.hadoop.hdfs.protocol.ClientProtocol#restoreFailedStorage(String arg)
    */
-  public boolean restoreFailedStorage(String arg)
+  public boolean restoreFailedStorage(String arg) throws IOException {
-      throws AccessControlException, IOException {
     return dfs.restoreFailedStorage(arg);
   }
 
@@ -1332,8 +1312,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(f);
     return new FileSystemLinkResolver<FileStatus>() {
       @Override
-      public FileStatus doCall(final Path p) throws IOException,
+      public FileStatus doCall(final Path p) throws IOException {
-          UnresolvedLinkException {
         HdfsFileStatus fi = dfs.getFileInfo(getPathName(p));
         if (fi != null) {
           return fi.makeQualified(getUri(), p);
@@ -1352,10 +1331,7 @@ public class DistributedFileSystem extends FileSystem {
   @SuppressWarnings("deprecation")
   @Override
   public void createSymlink(final Path target, final Path link,
-      final boolean createParent) throws AccessControlException,
+      final boolean createParent) throws IOException {
-      FileAlreadyExistsException, FileNotFoundException,
-      ParentNotDirectoryException, UnsupportedFileSystemException, 
-      IOException {
     if (!FileSystem.areSymlinksEnabled()) {
       throw new UnsupportedOperationException("Symlinks not supported");
     }
@@ -1363,14 +1339,12 @@ public class DistributedFileSystem extends FileSystem {
     final Path absF = fixRelativePart(link);
     new FileSystemLinkResolver<Void>() {
       @Override
-      public Void doCall(final Path p) throws IOException,
+      public Void doCall(final Path p) throws IOException {
-          UnresolvedLinkException {
         dfs.createSymlink(target.toString(), getPathName(p), createParent);
         return null;
       }
       @Override
-      public Void next(final FileSystem fs, final Path p)
+      public Void next(final FileSystem fs, final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         fs.createSymlink(target, p, createParent);
         return null;
       }
@@ -1383,15 +1357,12 @@ public class DistributedFileSystem extends FileSystem {
   }
 
   @Override
-  public FileStatus getFileLinkStatus(final Path f)
+  public FileStatus getFileLinkStatus(final Path f) throws IOException {
-      throws AccessControlException, FileNotFoundException,
-      UnsupportedFileSystemException, IOException {
     statistics.incrementReadOps(1);
     final Path absF = fixRelativePart(f);
     FileStatus status = new FileSystemLinkResolver<FileStatus>() {
       @Override
-      public FileStatus doCall(final Path p) throws IOException,
+      public FileStatus doCall(final Path p) throws IOException {
-          UnresolvedLinkException {
         HdfsFileStatus fi = dfs.getFileLinkInfo(getPathName(p));
         if (fi != null) {
           return fi.makeQualified(getUri(), p);
@@ -1401,7 +1372,7 @@ public class DistributedFileSystem extends FileSystem {
       }
       @Override
       public FileStatus next(final FileSystem fs, final Path p)
-        throws IOException, UnresolvedLinkException {
+          throws IOException {
         return fs.getFileLinkStatus(p);
       }
     }.resolve(this, absF);
@@ -1415,14 +1386,12 @@ public class DistributedFileSystem extends FileSystem {
   }
 
   @Override
-  public Path getLinkTarget(final Path f) throws AccessControlException,
+  public Path getLinkTarget(final Path f) throws IOException {
-      FileNotFoundException, UnsupportedFileSystemException, IOException {
     statistics.incrementReadOps(1);
     final Path absF = fixRelativePart(f);
     return new FileSystemLinkResolver<Path>() {
       @Override
-      public Path doCall(final Path p) throws IOException,
+      public Path doCall(final Path p) throws IOException {
-          UnresolvedLinkException {
         HdfsFileStatus fi = dfs.getFileLinkInfo(getPathName(p));
         if (fi != null) {
           return fi.makeQualified(getUri(), p).getSymlink();
@@ -1431,8 +1400,7 @@ public class DistributedFileSystem extends FileSystem {
         }
       }
       @Override
-      public Path next(final FileSystem fs, final Path p)
+      public Path next(final FileSystem fs, final Path p) throws IOException {
-        throws IOException, UnresolvedLinkException {
         return fs.getLinkTarget(p);
       }
     }.resolve(this, absF);
@@ -1454,8 +1422,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(f);
     return new FileSystemLinkResolver<FileChecksum>() {
       @Override
-      public FileChecksum doCall(final Path p)
+      public FileChecksum doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         return dfs.getFileChecksum(getPathName(p), Long.MAX_VALUE);
       }
 
@@ -1474,8 +1441,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(f);
     return new FileSystemLinkResolver<FileChecksum>() {
       @Override
-      public FileChecksum doCall(final Path p)
+      public FileChecksum doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         return dfs.getFileChecksum(getPathName(p), length);
       }
 
@@ -1483,7 +1449,7 @@ public class DistributedFileSystem extends FileSystem {
       public FileChecksum next(final FileSystem fs, final Path p)
           throws IOException {
         if (fs instanceof DistributedFileSystem) {
-          return ((DistributedFileSystem) fs).getFileChecksum(p, length);
+          return fs.getFileChecksum(p, length);
         } else {
           throw new UnsupportedFileSystemException(
               "getFileChecksum(Path, long) is not supported by "
@@ -1495,13 +1461,12 @@ public class DistributedFileSystem extends FileSystem {
 
   @Override
   public void setPermission(Path p, final FsPermission permission
-      ) throws IOException {
+  ) throws IOException {
     statistics.incrementWriteOps(1);
     Path absF = fixRelativePart(p);
     new FileSystemLinkResolver<Void>() {
       @Override
-      public Void doCall(final Path p)
+      public Void doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         dfs.setPermission(getPathName(p), permission);
         return null;
       }
@@ -1516,8 +1481,8 @@ public class DistributedFileSystem extends FileSystem {
   }
 
   @Override
-  public void setOwner(Path p, final String username, final String groupname
+  public void setOwner(Path p, final String username, final String groupname)
-      ) throws IOException {
+      throws IOException {
     if (username == null && groupname == null) {
       throw new IOException("username == null && groupname == null");
     }
@@ -1525,8 +1490,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(p);
     new FileSystemLinkResolver<Void>() {
       @Override
-      public Void doCall(final Path p)
+      public Void doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         dfs.setOwner(getPathName(p), username, groupname);
         return null;
       }
@@ -1541,14 +1505,13 @@ public class DistributedFileSystem extends FileSystem {
   }
 
   @Override
-  public void setTimes(Path p, final long mtime, final long atime
+  public void setTimes(Path p, final long mtime, final long atime)
-      ) throws IOException {
+      throws IOException {
     statistics.incrementWriteOps(1);
     Path absF = fixRelativePart(p);
     new FileSystemLinkResolver<Void>() {
       @Override
-      public Void doCall(final Path p)
+      public Void doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         dfs.setTimes(getPathName(p), mtime, atime);
         return null;
       }
@@ -1571,9 +1534,7 @@ public class DistributedFileSystem extends FileSystem {
   @Override
   public Token<DelegationTokenIdentifier> getDelegationToken(String renewer)
       throws IOException {
-    Token<DelegationTokenIdentifier> result =
+    return dfs.getDelegationToken(renewer == null ? null : new Text(renewer));
-      dfs.getDelegationToken(renewer == null ? null : new Text(renewer));
-    return result;
   }
 
   /**
@@ -1627,8 +1588,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(path);
     new FileSystemLinkResolver<Void>() {
       @Override
-      public Void doCall(final Path p)
+      public Void doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         dfs.allowSnapshot(getPathName(p));
         return null;
       }
@@ -1654,8 +1614,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(path);
     new FileSystemLinkResolver<Void>() {
       @Override
-      public Void doCall(final Path p)
+      public Void doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         dfs.disallowSnapshot(getPathName(p));
         return null;
       }
@@ -1682,8 +1641,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(path);
     return new FileSystemLinkResolver<Path>() {
       @Override
-      public Path doCall(final Path p)
+      public Path doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         return new Path(dfs.createSnapshot(getPathName(p), snapshotName));
       }
 
@@ -1708,8 +1666,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(path);
     new FileSystemLinkResolver<Void>() {
       @Override
-      public Void doCall(final Path p)
+      public Void doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         dfs.renameSnapshot(getPathName(p), snapshotOldName, snapshotNewName);
         return null;
       }
@@ -1745,8 +1702,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(snapshotDir);
     new FileSystemLinkResolver<Void>() {
       @Override
-      public Void doCall(final Path p)
+      public Void doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         dfs.deleteSnapshot(getPathName(p), snapshotName);
         return null;
       }
@@ -1778,8 +1734,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(snapshotDir);
     return new FileSystemLinkResolver<SnapshotDiffReport>() {
       @Override
-      public SnapshotDiffReport doCall(final Path p)
+      public SnapshotDiffReport doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         return dfs.getSnapshotDiffReport(getPathName(p), fromSnapshot,
             toSnapshot);
       }
@@ -1812,8 +1767,7 @@ public class DistributedFileSystem extends FileSystem {
     Path absF = fixRelativePart(src);
     return new FileSystemLinkResolver<Boolean>() {
       @Override
-      public Boolean doCall(final Path p)
+      public Boolean doCall(final Path p) throws IOException {
-          throws IOException, UnresolvedLinkException {
         return dfs.isFileClosed(getPathName(p));
       }
 
@@ -2043,8 +1997,7 @@ public class DistributedFileSystem extends FileSystem {
         return null;
       }
       @Override
-      public Void next(final FileSystem fs, final Path p)
+      public Void next(final FileSystem fs, final Path p) throws IOException {
-        throws IOException, UnresolvedLinkException {
         fs.removeDefaultAcl(p);
         return null;
       }
@@ -2064,8 +2017,7 @@ public class DistributedFileSystem extends FileSystem {
         return null;
       }
       @Override
-      public Void next(final FileSystem fs, final Path p)
+      public Void next(final FileSystem fs, final Path p) throws IOException {
-        throws IOException, UnresolvedLinkException {
         fs.removeAcl(p);
         return null;
       }
@@ -2076,7 +2028,8 @@ public class DistributedFileSystem extends FileSystem {
    * {@inheritDoc}
    */
   @Override
-  public void setAcl(Path path, final List<AclEntry> aclSpec) throws IOException {
+  public void setAcl(Path path, final List<AclEntry> aclSpec)
+      throws IOException {
     Path absF = fixRelativePart(path);
     new FileSystemLinkResolver<Void>() {
       @Override
@@ -2106,7 +2059,7 @@ public class DistributedFileSystem extends FileSystem {
       }
       @Override
       public AclStatus next(final FileSystem fs, final Path p)
-        throws IOException, UnresolvedLinkException {
+          throws IOException {
         return fs.getAclStatus(p);
       }
     }.resolve(this, absF);
@@ -2114,12 +2067,11 @@ public class DistributedFileSystem extends FileSystem {
 
   /* HDFS only */
   public void createEncryptionZone(final Path path, final String keyName)
-    throws IOException {
+      throws IOException {
     Path absF = fixRelativePart(path);
     new FileSystemLinkResolver<Void>() {
       @Override
-      public Void doCall(final Path p) throws IOException,
+      public Void doCall(final Path p) throws IOException {
-          UnresolvedLinkException {
         dfs.createEncryptionZone(getPathName(p), keyName);
         return null;
       }
@@ -2142,13 +2094,12 @@ public class DistributedFileSystem extends FileSystem {
 
   /* HDFS only */
   public EncryptionZone getEZForPath(final Path path)
-          throws IOException {
+      throws IOException {
     Preconditions.checkNotNull(path);
     Path absF = fixRelativePart(path);
     return new FileSystemLinkResolver<EncryptionZone>() {
       @Override
-      public EncryptionZone doCall(final Path p) throws IOException,
+      public EncryptionZone doCall(final Path p) throws IOException {
-          UnresolvedLinkException {
         return dfs.getEZForPath(getPathName(p));
       }
 
@@ -2203,8 +2154,7 @@ public class DistributedFileSystem extends FileSystem {
         return dfs.getXAttr(getPathName(p), name);
       }
       @Override
-      public byte[] next(final FileSystem fs, final Path p)
+      public byte[] next(final FileSystem fs, final Path p) throws IOException {
-        throws IOException, UnresolvedLinkException {
         return fs.getXAttr(p, name);
       }
     }.resolve(this, absF);
@@ -2220,7 +2170,7 @@ public class DistributedFileSystem extends FileSystem {
       }
       @Override
       public Map<String, byte[]> next(final FileSystem fs, final Path p)
-        throws IOException, UnresolvedLinkException {
+          throws IOException {
         return fs.getXAttrs(p);
       }
     }.resolve(this, absF);
@@ -2237,7 +2187,7 @@ public class DistributedFileSystem extends FileSystem {
       }
       @Override
       public Map<String, byte[]> next(final FileSystem fs, final Path p)
-        throws IOException, UnresolvedLinkException {
+          throws IOException {
         return fs.getXAttrs(p, names);
       }
     }.resolve(this, absF);
@@ -2245,7 +2195,7 @@ public class DistributedFileSystem extends FileSystem {
 
   @Override
   public List<String> listXAttrs(Path path)
-          throws IOException {
+      throws IOException {
     final Path absF = fixRelativePart(path);
     return new FileSystemLinkResolver<List<String>>() {
       @Override
@@ -2254,7 +2204,7 @@ public class DistributedFileSystem extends FileSystem {
       }
       @Override
       public List<String> next(final FileSystem fs, final Path p)
-              throws IOException, UnresolvedLinkException {
+          throws IOException {
         return fs.listXAttrs(p);
       }
     }.resolve(this, absF);

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/ExtendedBlockId.java

@@ -76,7 +76,6 @@ final public class ExtendedBlockId {
 
   @Override
   public String toString() {
-    return new StringBuilder().append(blockId).
+    return String.valueOf(blockId) + "_" + bpId;
-        append("_").append(bpId).toString();
   }
 }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/ExternalBlockReader.java

@@ -79,7 +79,7 @@ public final class ExternalBlockReader implements BlockReader {
   }
 
   @Override
-  public int available() throws IOException {
+  public int available() {
     // We return the amount of bytes between the current offset and the visible
     // length.  Some of the other block readers return a shorter length than
     // that.  The only advantage to returning a shorter length is that the

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/KeyProviderCache.java

@@ -17,7 +17,6 @@
  */
 package org.apache.hadoop.hdfs;
 
-import java.io.IOException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.concurrent.Callable;
@@ -37,10 +36,13 @@ import com.google.common.cache.RemovalNotification;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import javax.annotation.Nonnull;
+
 @InterfaceAudience.Private
 public class KeyProviderCache {
 
-  public static final Logger LOG = LoggerFactory.getLogger(KeyProviderCache.class);
+  public static final Logger LOG = LoggerFactory.getLogger(
+      KeyProviderCache.class);
 
   private final Cache<URI, KeyProvider> cache;
 
@@ -50,14 +52,14 @@ public class KeyProviderCache {
         .removalListener(new RemovalListener<URI, KeyProvider>() {
           @Override
           public void onRemoval(
-              RemovalNotification<URI, KeyProvider> notification) {
+              @Nonnull RemovalNotification<URI, KeyProvider> notification) {
             try {
+              assert notification.getValue() != null;
               notification.getValue().close();
             } catch (Throwable e) {
               LOG.error(
                   "Error closing KeyProvider with uri ["
                       + notification.getKey() + "]", e);
-              ;
             }
           }
         })
@@ -83,8 +85,8 @@ public class KeyProviderCache {
   }
 
   private URI createKeyProviderURI(Configuration conf) {
-    final String providerUriStr =
+    final String providerUriStr = conf.getTrimmed(
-        conf.getTrimmed(HdfsClientConfigKeys.DFS_ENCRYPTION_KEY_PROVIDER_URI, "");
+        HdfsClientConfigKeys.DFS_ENCRYPTION_KEY_PROVIDER_URI, "");
     // No provider set in conf
     if (providerUriStr.isEmpty()) {
       LOG.error("Could not find uri with key ["
@@ -104,9 +106,9 @@ public class KeyProviderCache {
   }
 
   @VisibleForTesting
-  public void setKeyProvider(Configuration conf, KeyProvider keyProvider)
+  public void setKeyProvider(Configuration conf, KeyProvider keyProvider) {
-      throws IOException {
     URI uri = createKeyProviderURI(conf);
+    assert uri != null;
     cache.put(uri, keyProvider);
   }
 }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/NameNodeProxiesClient.java

@@ -297,13 +297,11 @@ public class NameNodeProxiesClient {
    * @param failoverProxyProvider Failover proxy provider
    * @return an object containing both the proxy and the associated
    *         delegation token service it corresponds to
-   * @throws IOException
    */
   @SuppressWarnings("unchecked")
   public static <T> ProxyAndInfo<T> createHAProxy(
       Configuration conf, URI nameNodeUri, Class<T> xface,
-      AbstractNNFailoverProxyProvider<T> failoverProxyProvider)
+      AbstractNNFailoverProxyProvider<T> failoverProxyProvider) {
-      throws IOException {
     Preconditions.checkNotNull(failoverProxyProvider);
     // HA case
     DfsClientConf config = new DfsClientConf(conf);

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/PeerCache.java

@@ -32,7 +32,6 @@ import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.hdfs.net.Peer;
 import org.apache.hadoop.hdfs.protocol.DatanodeID;
 import org.apache.hadoop.hdfs.util.IOUtilsClient;
-import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.util.Daemon;
 import org.apache.hadoop.util.Time;
 import org.slf4j.Logger;
@@ -92,7 +91,7 @@ public class PeerCache {
   private Daemon daemon;
   /** A map for per user per datanode. */
   private final LinkedListMultimap<Key, Value> multimap =
-    LinkedListMultimap.create();
+      LinkedListMultimap.create();
   private final int capacity;
   private final long expiryPeriod;
 
@@ -109,12 +108,12 @@ public class PeerCache {
   }
 
   private boolean isDaemonStarted() {
-    return (daemon == null)? false: true;
+    return daemon != null;
   }
 
   private synchronized void startExpiryDaemon() {
     // start daemon only if not already started
-    if (isDaemonStarted() == true) {
+    if (isDaemonStarted()) {
       return;
     }
 
@@ -215,12 +214,11 @@ public class PeerCache {
   private synchronized void evictExpired(long expiryPeriod) {
     while (multimap.size() != 0) {
       Iterator<Entry<Key, Value>> iter =
-        multimap.entries().iterator();
+          multimap.entries().iterator();
       Entry<Key, Value> entry = iter.next();
       // if oldest socket expired, remove it
       if (entry == null ||
-        Time.monotonicNow() - entry.getValue().getTime() <
+          Time.monotonicNow() - entry.getValue().getTime() < expiryPeriod) {
-        expiryPeriod) {
         break;
       }
       IOUtilsClient.cleanup(LOG, entry.getValue().getPeer());
@@ -235,8 +233,7 @@ public class PeerCache {
     // We can get the oldest element immediately, because of an interesting
     // property of LinkedListMultimap: its iterator traverses entries in the
     // order that they were added.
-    Iterator<Entry<Key, Value>> iter =
+    Iterator<Entry<Key, Value>> iter = multimap.entries().iterator();
-      multimap.entries().iterator();
     if (!iter.hasNext()) {
       throw new IllegalStateException("Cannot evict from empty cache! " +
         "capacity: " + capacity);
@@ -247,8 +244,8 @@ public class PeerCache {
   }
 
   /**
-   * Periodically check in the cache and expire the entries
+   * Periodically check in the cache and expire the entries older than
-   * older than expiryPeriod minutes
+   * expiryPeriod minutes.
    */
   private void run() throws InterruptedException {
     for(long lastExpiryTime = Time.monotonicNow();

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/RemoteBlockReader.java

@@ -55,7 +55,8 @@ import org.slf4j.LoggerFactory;
 
 /**
  * @deprecated this is an old implementation that is being left around
- * in case any issues spring up with the new {@link RemoteBlockReader2} implementation.
+ * in case any issues spring up with the new {@link RemoteBlockReader2}
+ * implementation.
  * It will be removed in the next release.
  */
 @InterfaceAudience.Private
@@ -79,7 +80,7 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
   private final long blockId;
 
   /** offset in block of of first chunk - may be less than startOffset
-      if startOffset is not chunk-aligned */
+   if startOffset is not chunk-aligned */
   private final long firstChunkOffset;
 
   private final int bytesPerChecksum;
@@ -119,7 +120,7 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
    */
   @Override
   public synchronized int read(byte[] buf, int off, int len)
-                               throws IOException {
+      throws IOException {
 
     // This has to be set here, *before* the skip, since we can
     // hit EOS during the skip, in the case that our entire read
@@ -168,7 +169,7 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
   @Override
   public int read() throws IOException {
     throw new IOException("read() is not expected to be invoked. " +
-                          "Use read(buf, off, len) instead.");
+        "Use read(buf, off, len) instead.");
   }
 
   @Override
@@ -188,7 +189,7 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
   @Override
   protected long getChunkPosition(long pos) {
     throw new RuntimeException("getChunkPosition() is not supported, " +
-                               "since seek is not required");
+        "since seek is not required");
   }
 
   /**
@@ -198,7 +199,7 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
    */
   private void adjustChecksumBytes(int dataLen) {
     int requiredSize =
-      ((dataLen + bytesPerChecksum - 1)/bytesPerChecksum)*checksumSize;
+        ((dataLen + bytesPerChecksum - 1)/bytesPerChecksum)*checksumSize;
     if (checksumBytes == null || requiredSize > checksumBytes.capacity()) {
       checksumBytes =  ByteBuffer.wrap(new byte[requiredSize]);
     } else {
@@ -209,20 +210,17 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
 
   @Override
   protected synchronized int readChunk(long pos, byte[] buf, int offset,
-                                       int len, byte[] checksumBuf) 
+      int len, byte[] checksumBuf)
-                                       throws IOException {
+      throws IOException {
-    TraceScope scope = tracer.
+    try (TraceScope ignored = tracer.newScope(
-        newScope("RemoteBlockReader#readChunk(" + blockId + ")");
+        "RemoteBlockReader#readChunk(" + blockId + ")")) {
-    try {
       return readChunkImpl(pos, buf, offset, len, checksumBuf);
-    } finally {
-      scope.close();
     }
   }
 
   private synchronized int readChunkImpl(long pos, byte[] buf, int offset,
-                                     int len, byte[] checksumBuf)
+      int len, byte[] checksumBuf)
-                                     throws IOException {
+      throws IOException {
     // Read one chunk.
     if (eos) {
       // Already hit EOF
@@ -241,7 +239,7 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
     // for the same chunk we expect to be reading from the DN.
     if ( (pos + firstChunkOffset) != chunkOffset ) {
       throw new IOException("Mismatch in pos : " + pos + " + " +
-                            firstChunkOffset + " != " + chunkOffset);
+          firstChunkOffset + " != " + chunkOffset);
     }
 
     // Read next packet if the previous packet has been read completely.
@@ -254,8 +252,8 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
 
       // Sanity check the lengths
       if (!header.sanityCheck(lastSeqNo)) {
-           throw new IOException("BlockReader: error in packet header " +
+        throw new IOException("BlockReader: error in packet header " +
-                                 header);
+            header);
       }
 
       lastSeqNo = header.getSeqno();
@@ -263,7 +261,7 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
       adjustChecksumBytes(header.getDataLen());
       if (header.getDataLen() > 0) {
         IOUtils.readFully(in, checksumBytes.array(), 0,
-                          checksumBytes.limit());
+            checksumBytes.limit());
       }
     }
 
@@ -284,14 +282,14 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
       // How many chunks we can fit in databuffer
       //  - note this is a floor since we always read full chunks
       int chunksCanFit = Math.min(len / bytesPerChecksum,
-                                  checksumBuf.length / checksumSize);
+          checksumBuf.length / checksumSize);
 
       // How many chunks should we read
       checksumsToRead = Math.min(chunksLeft, chunksCanFit);
       // How many bytes should we actually read
       bytesToRead = Math.min(
-        checksumsToRead * bytesPerChecksum, // full chunks
+          checksumsToRead * bytesPerChecksum, // full chunks
-        dataLeft); // in case we have a partial
+          dataLeft); // in case we have a partial
     } else {
       // no checksum
       bytesToRead = Math.min(dataLeft, len);
@@ -328,7 +326,7 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
       if (!hdr.isLastPacketInBlock() ||
           hdr.getDataLen() != 0) {
         throw new IOException("Expected empty end-of-read packet! Header: " +
-                              hdr);
+            hdr);
       }
 
       eos = true;
@@ -347,11 +345,11 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
       DatanodeID datanodeID, PeerCache peerCache, Tracer tracer) {
     // Path is used only for printing block and file information in debug
     super(new Path("/" + Block.BLOCK_FILE_PREFIX + blockId +
-                    ":" + bpid + ":of:"+ file)/*too non path-like?*/,
+            ":" + bpid + ":of:"+ file)/*too non path-like?*/,
-          1, verifyChecksum,
+        1, verifyChecksum,
-          checksum.getChecksumSize() > 0? checksum : null, 
+        checksum.getChecksumSize() > 0? checksum : null,
-          checksum.getBytesPerChecksum(),
+        checksum.getBytesPerChecksum(),
-          checksum.getChecksumSize());
+        checksum.getChecksumSize());
 
     this.isLocal = DFSUtilClient.isLocalAddress(NetUtils.
         createSocketAddr(datanodeID.getXferAddr()));
@@ -394,16 +392,16 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
    * @return New BlockReader instance, or null on error.
    */
   public static RemoteBlockReader newBlockReader(String file,
-                                     ExtendedBlock block, 
+      ExtendedBlock block,
-                                     Token<BlockTokenIdentifier> blockToken,
+      Token<BlockTokenIdentifier> blockToken,
-                                     long startOffset, long len,
+      long startOffset, long len,
-                                     int bufferSize, boolean verifyChecksum,
+      int bufferSize, boolean verifyChecksum,
-                                     String clientName, Peer peer,
+      String clientName, Peer peer,
-                                     DatanodeID datanodeID,
+      DatanodeID datanodeID,
-                                     PeerCache peerCache,
+      PeerCache peerCache,
-                                     CachingStrategy cachingStrategy,
+      CachingStrategy cachingStrategy,
-                                     Tracer tracer)
+      Tracer tracer)
-                                       throws IOException {
+      throws IOException {
     // in and out will be closed when sock is closed (by the caller)
     final DataOutputStream out =
         new DataOutputStream(new BufferedOutputStream(peer.getOutputStream()));
@@ -421,7 +419,7 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
         PBHelperClient.vintPrefixed(in));
     RemoteBlockReader2.checkSuccess(status, peer, block, file);
     ReadOpChecksumInfoProto checksumInfo =
-      status.getReadOpChecksumInfo();
+        status.getReadOpChecksumInfo();
     DataChecksum checksum = DataTransferProtoUtil.fromProto(
         checksumInfo.getChecksum());
     //Warning when we get CHECKSUM_NULL?
@@ -432,8 +430,8 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
     if ( firstChunkOffset < 0 || firstChunkOffset > startOffset ||
         firstChunkOffset <= (startOffset - checksum.getBytesPerChecksum())) {
       throw new IOException("BlockReader: error in first chunk offset (" +
-                            firstChunkOffset + ") startOffset is " + 
+          firstChunkOffset + ") startOffset is " +
-                            startOffset + " for file " + file);
+          startOffset + " for file " + file);
     }
 
     return new RemoteBlockReader(file, block.getBlockPoolId(), block.getBlockId(),
@@ -479,7 +477,7 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
     } catch (IOException e) {
       // It's ok not to be able to send this. But something is probably wrong.
       LOG.info("Could not send read status (" + statusCode + ") to datanode " +
-               peer.getRemoteAddressString() + ": " + e.getMessage());
+          peer.getRemoteAddressString() + ": " + e.getMessage());
     }
   }
 
@@ -489,7 +487,7 @@ public class RemoteBlockReader extends FSInputChecker implements BlockReader {
   }
 
   @Override
-  public int available() throws IOException {
+  public int available() {
     // An optimistic estimate of how much data is available
     // to us without doing network I/O.
     return RemoteBlockReader2.TCP_WINDOW_SIZE;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/RemoteBlockReader2.java

@@ -134,18 +134,16 @@ public class RemoteBlockReader2  implements BlockReader {
 
   @Override
   public synchronized int read(byte[] buf, int off, int len)
-                               throws IOException {
+      throws IOException {
     UUID randomId = (LOG.isTraceEnabled() ? UUID.randomUUID() : null);
     LOG.trace("Starting read #{} file {} from datanode {}",
         randomId, filename, datanodeID.getHostName());
 
-    if (curDataSlice == null || curDataSlice.remaining() == 0 && bytesNeededToFinish > 0) {
+    if (curDataSlice == null ||
-      TraceScope scope = tracer.newScope(
+        curDataSlice.remaining() == 0 && bytesNeededToFinish > 0) {
-          "RemoteBlockReader2#readNextPacket(" + blockId + ")");
+      try (TraceScope ignored = tracer.newScope(
-      try {
+          "RemoteBlockReader2#readNextPacket(" + blockId + ")")) {
         readNextPacket();
-      } finally {
-        scope.close();
       }
     }
 
@@ -165,13 +163,11 @@ public class RemoteBlockReader2  implements BlockReader {
 
   @Override
   public synchronized int read(ByteBuffer buf) throws IOException {
-    if (curDataSlice == null || curDataSlice.remaining() == 0 && bytesNeededToFinish > 0) {
+    if (curDataSlice == null ||
-      TraceScope scope = tracer.newScope(
+        (curDataSlice.remaining() == 0 && bytesNeededToFinish > 0)) {
-          "RemoteBlockReader2#readNextPacket(" + blockId + ")");
+      try (TraceScope ignored = tracer.newScope(
-      try {
+          "RemoteBlockReader2#readNextPacket(" + blockId + ")")) {
         readNextPacket();
-      } finally {
-        scope.close();
       }
     }
     if (curDataSlice.remaining() == 0) {
@@ -200,8 +196,8 @@ public class RemoteBlockReader2  implements BlockReader {
 
     // Sanity check the lengths
     if (!curHeader.sanityCheck(lastSeqNo)) {
-         throw new IOException("BlockReader: error in packet header " +
+      throw new IOException("BlockReader: error in packet header " +
-                               curHeader);
+          curHeader);
     }
 
     if (curHeader.getDataLen() > 0) {
@@ -209,8 +205,9 @@ public class RemoteBlockReader2  implements BlockReader {
       int checksumsLen = chunks * checksumSize;
 
       assert packetReceiver.getChecksumSlice().capacity() == checksumsLen :
-        "checksum slice capacity=" + packetReceiver.getChecksumSlice().capacity() + 
+          "checksum slice capacity=" +
-          " checksumsLen=" + checksumsLen;
+              packetReceiver.getChecksumSlice().capacity() +
+              " checksumsLen=" + checksumsLen;
 
       lastSeqNo = curHeader.getSeqno();
       if (verifyChecksum && curDataSlice.remaining() > 0) {
@@ -251,7 +248,8 @@ public class RemoteBlockReader2  implements BlockReader {
     long skipped = 0;
     while (skipped < n) {
       long needToSkip = n - skipped;
-      if (curDataSlice == null || curDataSlice.remaining() == 0 && bytesNeededToFinish > 0) {
+      if (curDataSlice == null ||
+          curDataSlice.remaining() == 0 && bytesNeededToFinish > 0) {
         readNextPacket();
       }
       if (curDataSlice.remaining() == 0) {
@@ -273,13 +271,13 @@ public class RemoteBlockReader2  implements BlockReader {
 
     PacketHeader trailer = packetReceiver.getHeader();
     if (!trailer.isLastPacketInBlock() ||
-       trailer.getDataLen() != 0) {
+        trailer.getDataLen() != 0) {
       throw new IOException("Expected empty end-of-read packet! Header: " +
-                            trailer);
+          trailer);
     }
   }
 
-  protected RemoteBlockReader2(String file, String bpid, long blockId,
+  protected RemoteBlockReader2(String file, long blockId,
       DataChecksum checksum, boolean verifyChecksum,
       long startOffset, long firstChunkOffset, long bytesToRead, Peer peer,
       DatanodeID datanodeID, PeerCache peerCache, Tracer tracer) {
@@ -335,7 +333,7 @@ public class RemoteBlockReader2  implements BlockReader {
     } catch (IOException e) {
       // It's ok not to be able to send this. But something is probably wrong.
       LOG.info("Could not send read status (" + statusCode + ") to datanode " +
-               peer.getRemoteAddressString() + ": " + e.getMessage());
+          peer.getRemoteAddressString() + ": " + e.getMessage());
     }
   }
 
@@ -346,9 +344,9 @@ public class RemoteBlockReader2  implements BlockReader {
       throws IOException {
 
     ClientReadStatusProto.newBuilder()
-      .setStatus(statusCode)
+        .setStatus(statusCode)
-      .build()
+        .build()
-      .writeDelimitedTo(out);
+        .writeDelimitedTo(out);
 
     out.flush();
   }
@@ -391,18 +389,18 @@ public class RemoteBlockReader2  implements BlockReader {
    * @return New BlockReader instance, or null on error.
    */
   public static BlockReader newBlockReader(String file,
-                                     ExtendedBlock block,
+      ExtendedBlock block,
-                                     Token<BlockTokenIdentifier> blockToken,
+      Token<BlockTokenIdentifier> blockToken,
-                                     long startOffset, long len,
+      long startOffset, long len,
-                                     boolean verifyChecksum,
+      boolean verifyChecksum,
-                                     String clientName,
+      String clientName,
-                                     Peer peer, DatanodeID datanodeID,
+      Peer peer, DatanodeID datanodeID,
-                                     PeerCache peerCache,
+      PeerCache peerCache,
-                                     CachingStrategy cachingStrategy,
+      CachingStrategy cachingStrategy,
-                                     Tracer tracer) throws IOException {
+      Tracer tracer) throws IOException {
     // in and out will be closed when sock is closed (by the caller)
     final DataOutputStream out = new DataOutputStream(new BufferedOutputStream(
-          peer.getOutputStream()));
+        peer.getOutputStream()));
     new Sender(out).readBlock(block, blockToken, clientName, startOffset, len,
         verifyChecksum, cachingStrategy);
 
@@ -415,7 +413,7 @@ public class RemoteBlockReader2  implements BlockReader {
         PBHelperClient.vintPrefixed(in));
     checkSuccess(status, peer, block, file);
     ReadOpChecksumInfoProto checksumInfo =
-      status.getReadOpChecksumInfo();
+        status.getReadOpChecksumInfo();
     DataChecksum checksum = DataTransferProtoUtil.fromProto(
         checksumInfo.getChecksum());
     //Warning when we get CHECKSUM_NULL?
@@ -426,13 +424,13 @@ public class RemoteBlockReader2  implements BlockReader {
     if ( firstChunkOffset < 0 || firstChunkOffset > startOffset ||
         firstChunkOffset <= (startOffset - checksum.getBytesPerChecksum())) {
       throw new IOException("BlockReader: error in first chunk offset (" +
-                            firstChunkOffset + ") startOffset is " +
+          firstChunkOffset + ") startOffset is " +
-                            startOffset + " for file " + file);
+          startOffset + " for file " + file);
     }
 
-    return new RemoteBlockReader2(file, block.getBlockPoolId(), block.getBlockId(),
+    return new RemoteBlockReader2(file, block.getBlockId(), checksum,
-        checksum, verifyChecksum, startOffset, firstChunkOffset, len, peer,
+        verifyChecksum, startOffset, firstChunkOffset, len, peer, datanodeID,
-        datanodeID, peerCache, tracer);
+        peerCache, tracer);
   }
 
   static void checkSuccess(
@@ -440,16 +438,16 @@ public class RemoteBlockReader2  implements BlockReader {
       ExtendedBlock block, String file)
       throws IOException {
     String logInfo = "for OP_READ_BLOCK"
-      + ", self=" + peer.getLocalAddressString()
+        + ", self=" + peer.getLocalAddressString()
-      + ", remote=" + peer.getRemoteAddressString()
+        + ", remote=" + peer.getRemoteAddressString()
-      + ", for file " + file
+        + ", for file " + file
-      + ", for pool " + block.getBlockPoolId()
+        + ", for pool " + block.getBlockPoolId()
-      + " block " + block.getBlockId() + "_" + block.getGenerationStamp();
+        + " block " + block.getBlockId() + "_" + block.getGenerationStamp();
     DataTransferProtoUtil.checkBlockOpStatus(status, logInfo);
   }
 
   @Override
-  public int available() throws IOException {
+  public int available() {
     // An optimistic estimate of how much data is available
     // to us without doing network I/O.
     return TCP_WINDOW_SIZE;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/XAttrHelper.java

@@ -77,10 +77,9 @@ public class XAttrHelper {
       throw new HadoopIllegalArgumentException("An XAttr name must be " +
           "prefixed with user/trusted/security/system/raw, followed by a '.'");
     }
-    XAttr xAttr = (new XAttr.Builder()).setNameSpace(ns).setName(name.
-        substring(prefixIndex + 1)).setValue(value).build();
 
-    return xAttr;
+    return (new XAttr.Builder()).setNameSpace(ns).setName(name.
+        substring(prefixIndex + 1)).setValue(value).build();
   }
 
   /**

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/client/HdfsClientConfigKeys.java

@@ -31,7 +31,8 @@ public interface HdfsClientConfigKeys {
   long    DFS_BLOCK_SIZE_DEFAULT = 128*1024*1024;
   String  DFS_REPLICATION_KEY = "dfs.replication";
   short   DFS_REPLICATION_DEFAULT = 3;
-  String  DFS_WEBHDFS_USER_PATTERN_KEY = "dfs.webhdfs.user.provider.user.pattern";
+  String  DFS_WEBHDFS_USER_PATTERN_KEY =
+      "dfs.webhdfs.user.provider.user.pattern";
   String  DFS_WEBHDFS_USER_PATTERN_DEFAULT = "^[A-Za-z_][A-Za-z0-9._-]*[$]?$";
   String DFS_WEBHDFS_ACL_PERMISSION_PATTERN_DEFAULT =
       "^(default:)?(user|group|mask|other):[[A-Za-z_][A-Za-z0-9._-]]*:([rwx-]{3})?(,(default:)?(user|group|mask|other):[[A-Za-z_][A-Za-z0-9._-]]*:([rwx-]{3})?)*$";
@@ -125,7 +126,8 @@ public interface HdfsClientConfigKeys {
       "dfs.datanode.hdfs-blocks-metadata.enabled";
   boolean DFS_HDFS_BLOCKS_METADATA_ENABLED_DEFAULT = false;
 
-  String  DFS_DATANODE_KERBEROS_PRINCIPAL_KEY = "dfs.datanode.kerberos.principal";
+  String  DFS_DATANODE_KERBEROS_PRINCIPAL_KEY =
+      "dfs.datanode.kerberos.principal";
   String  DFS_DATANODE_READAHEAD_BYTES_KEY = "dfs.datanode.readahead.bytes";
   long    DFS_DATANODE_READAHEAD_BYTES_DEFAULT = 4 * 1024 * 1024; // 4MB
   String  DFS_ENCRYPTION_KEY_PROVIDER_URI = "dfs.encryption.key.provider.uri";
@@ -142,7 +144,8 @@ public interface HdfsClientConfigKeys {
       "dfs.encrypt.data.transfer.cipher.key.bitlength";
   int    DFS_ENCRYPT_DATA_TRANSFER_CIPHER_KEY_BITLENGTH_DEFAULT = 128;
 
-  String DFS_TRUSTEDCHANNEL_RESOLVER_CLASS = "dfs.trustedchannel.resolver.class";
+  String DFS_TRUSTEDCHANNEL_RESOLVER_CLASS =
+      "dfs.trustedchannel.resolver.class";
 
   String REPLICA_ACCESSOR_BUILDER_CLASSES_KEY =
       PREFIX + "replica.accessor.builder.classes";
@@ -165,9 +168,11 @@ public interface HdfsClientConfigKeys {
     String  POLICY_SPEC_KEY = PREFIX + "policy.spec";
     String  POLICY_SPEC_DEFAULT = "10000,6,60000,10"; //t1,n1,t2,n2,...
 
-    String  TIMES_GET_LAST_BLOCK_LENGTH_KEY = PREFIX + "times.get-last-block-length";
+    String  TIMES_GET_LAST_BLOCK_LENGTH_KEY =
+        PREFIX + "times.get-last-block-length";
     int     TIMES_GET_LAST_BLOCK_LENGTH_DEFAULT = 3;
-    String  INTERVAL_GET_LAST_BLOCK_LENGTH_KEY = PREFIX + "interval-ms.get-last-block-length";
+    String  INTERVAL_GET_LAST_BLOCK_LENGTH_KEY =
+        PREFIX + "interval-ms.get-last-block-length";
     int     INTERVAL_GET_LAST_BLOCK_LENGTH_DEFAULT = 4000;
 
     String  MAX_ATTEMPTS_KEY = PREFIX + "max.attempts";
@@ -190,7 +195,8 @@ public interface HdfsClientConfigKeys {
     int     SLEEPTIME_MAX_DEFAULT = 15000;
     String  CONNECTION_RETRIES_KEY = PREFIX + "connection.retries";
     int     CONNECTION_RETRIES_DEFAULT = 0;
-    String  CONNECTION_RETRIES_ON_SOCKET_TIMEOUTS_KEY = PREFIX + "connection.retries.on.timeouts";
+    String  CONNECTION_RETRIES_ON_SOCKET_TIMEOUTS_KEY =
+        PREFIX + "connection.retries.on.timeouts";
     int     CONNECTION_RETRIES_ON_SOCKET_TIMEOUTS_DEFAULT = 0;
   }
 
@@ -200,7 +206,8 @@ public interface HdfsClientConfigKeys {
 
     String  MAX_PACKETS_IN_FLIGHT_KEY = PREFIX + "max-packets-in-flight";
     int     MAX_PACKETS_IN_FLIGHT_DEFAULT = 80;
-    String  EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL_KEY = PREFIX + "exclude.nodes.cache.expiry.interval.millis";
+    String  EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL_KEY =
+        PREFIX + "exclude.nodes.cache.expiry.interval.millis";
     long    EXCLUDE_NODES_CACHE_EXPIRY_INTERVAL_DEFAULT = 10*MINUTE;
 
     interface ByteArrayManager {
@@ -212,7 +219,8 @@ public interface HdfsClientConfigKeys {
       int     COUNT_THRESHOLD_DEFAULT = 128;
       String  COUNT_LIMIT_KEY = PREFIX + "count-limit";
       int     COUNT_LIMIT_DEFAULT = 2048;
-      String  COUNT_RESET_TIME_PERIOD_MS_KEY = PREFIX + "count-reset-time-period-ms";
+      String  COUNT_RESET_TIME_PERIOD_MS_KEY =
+          PREFIX + "count-reset-time-period-ms";
       long    COUNT_RESET_TIME_PERIOD_MS_DEFAULT = 10*SECOND;
     }
   }
@@ -223,9 +231,11 @@ public interface HdfsClientConfigKeys {
 
     String  RETRIES_KEY = PREFIX + "retries";
     int     RETRIES_DEFAULT = 3;
-    String  LOCATEFOLLOWINGBLOCK_RETRIES_KEY = PREFIX + "locateFollowingBlock.retries";
+    String  LOCATEFOLLOWINGBLOCK_RETRIES_KEY =
+        PREFIX + "locateFollowingBlock.retries";
     int     LOCATEFOLLOWINGBLOCK_RETRIES_DEFAULT = 5;
-    String  LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_MS_KEY = PREFIX + "locateFollowingBlock.initial.delay.ms";
+    String  LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_MS_KEY =
+        PREFIX + "locateFollowingBlock.initial.delay.ms";
     int     LOCATEFOLLOWINGBLOCK_INITIAL_DELAY_MS_DEFAULT = 400;
 
     interface ReplaceDatanodeOnFailure {
@@ -267,7 +277,8 @@ public interface HdfsClientConfigKeys {
   interface ShortCircuit {
     String PREFIX = Read.PREFIX + "short.circuit.";
 
-    String  REPLICA_STALE_THRESHOLD_MS_KEY = PREFIX + "replica.stale.threshold.ms";
+    String  REPLICA_STALE_THRESHOLD_MS_KEY =
+        PREFIX + "replica.stale.threshold.ms";
     long    REPLICA_STALE_THRESHOLD_MS_DEFAULT = 30*MINUTE;
   }
 

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/client/HdfsDataInputStream.java

@@ -38,11 +38,11 @@ import com.google.common.base.Preconditions;
 @InterfaceAudience.Public
 @InterfaceStability.Evolving
 public class HdfsDataInputStream extends FSDataInputStream {
-  public HdfsDataInputStream(DFSInputStream in) throws IOException {
+  public HdfsDataInputStream(DFSInputStream in) {
     super(in);
   }
 
-  public HdfsDataInputStream(CryptoInputStream in) throws IOException {
+  public HdfsDataInputStream(CryptoInputStream in) {
     super(in);
     Preconditions.checkArgument(in.getWrappedStream() instanceof DFSInputStream,
         "CryptoInputStream should wrap a DFSInputStream");
@@ -63,7 +63,7 @@ public class HdfsDataInputStream extends FSDataInputStream {
    * @return the underlying output stream
    */
   public InputStream getWrappedStream() {
-      return in;
+    return in;
   }
 
   /**
@@ -93,7 +93,7 @@ public class HdfsDataInputStream extends FSDataInputStream {
    *
    * @return The visible length of the file.
    */
-  public long getVisibleLength() throws IOException {
+  public long getVisibleLength() {
     return getDFSInputStream().getFileLength();
   }
 

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/client/HdfsDataOutputStream.java

@@ -41,20 +41,21 @@ public class HdfsDataOutputStream extends FSDataOutputStream {
     super(out, stats, startPosition);
   }
 
-  public HdfsDataOutputStream(DFSOutputStream out, FileSystem.Statistics stats
+  public HdfsDataOutputStream(DFSOutputStream out, FileSystem.Statistics stats)
-      ) throws IOException {
+      throws IOException {
     this(out, stats, 0L);
   }
 
-  public HdfsDataOutputStream(CryptoOutputStream out, FileSystem.Statistics stats,
+  public HdfsDataOutputStream(CryptoOutputStream out,
-      long startPosition) throws IOException {
+      FileSystem.Statistics stats, long startPosition) throws IOException {
     super(out, stats, startPosition);
-    Preconditions.checkArgument(out.getWrappedStream() instanceof DFSOutputStream,
+    Preconditions.checkArgument(
+        out.getWrappedStream() instanceof DFSOutputStream,
         "CryptoOutputStream should wrap a DFSOutputStream");
   }
 
-  public HdfsDataOutputStream(CryptoOutputStream out, FileSystem.Statistics stats)
+  public HdfsDataOutputStream(CryptoOutputStream out,
-      throws IOException {
+      FileSystem.Statistics stats) throws IOException {
     this(out, stats, 0L);
   }
 
@@ -89,13 +90,13 @@ public class HdfsDataOutputStream extends FSDataOutputStream {
   public void hsync(EnumSet<SyncFlag> syncFlags) throws IOException {
     OutputStream wrappedStream = getWrappedStream();
     if (wrappedStream instanceof CryptoOutputStream) {
-      ((CryptoOutputStream) wrappedStream).flush();
+      wrappedStream.flush();
       wrappedStream = ((CryptoOutputStream) wrappedStream).getWrappedStream();
     }
     ((DFSOutputStream) wrappedStream).hsync(syncFlags);
   }
 
-  public static enum SyncFlag {
+  public enum SyncFlag {
 
     /**
      * When doing sync to DataNodes, also update the metadata (block length) in
@@ -107,6 +108,6 @@ public class HdfsDataOutputStream extends FSDataOutputStream {
      * Sync the data to DataNode, close the current block, and allocate a new
      * block
      */
-    END_BLOCK;
+    END_BLOCK
   }
 }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/client/impl/DfsClientConf.java

@@ -79,7 +79,6 @@ import static org.apache.hadoop.hdfs.client.HdfsClientConfigKeys.Retry;
 import static org.apache.hadoop.hdfs.client.HdfsClientConfigKeys.ShortCircuit;
 import static org.apache.hadoop.hdfs.client.HdfsClientConfigKeys.Write;
 
-import java.lang.Class;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -254,9 +253,8 @@ public class DfsClientConf {
 
   @SuppressWarnings("unchecked")
   private List<Class<? extends ReplicaAccessorBuilder>>
-      loadReplicaAccessorBuilderClasses(Configuration conf)
+      loadReplicaAccessorBuilderClasses(Configuration conf) {
-  {
+    String[] classNames = conf.getTrimmedStrings(
-    String classNames[] = conf.getTrimmedStrings(
         HdfsClientConfigKeys.REPLICA_ACCESSOR_BUILDER_CLASSES_KEY);
     if (classNames.length == 0) {
       return Collections.emptyList();
@@ -267,8 +265,8 @@ public class DfsClientConf {
     for (String className: classNames) {
       try {
         Class<? extends ReplicaAccessorBuilder> cls =
-          (Class<? extends ReplicaAccessorBuilder>)
+            (Class<? extends ReplicaAccessorBuilder>)
-            classLoader.loadClass(className);
+                classLoader.loadClass(className);
         classes.add(cls);
       } catch (Throwable t) {
         LOG.warn("Unable to load " + className, t);

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/client/impl/LeaseRenewer.java

@@ -42,8 +42,8 @@ import org.slf4j.LoggerFactory;
 
 /**
  * <p>
- * Used by {@link org.apache.hadoop.hdfs.DFSClient} for renewing file-being-written leases
+ * Used by {@link org.apache.hadoop.hdfs.DFSClient} for renewing
- * on the namenode.
+ * file-being-written leases on the namenode.
  * When a file is opened for write (create or append),
  * namenode stores a file lease for recording the identity of the writer.
  * The writer (i.e. the DFSClient) is required to renew the lease periodically.
@@ -57,7 +57,8 @@ import org.slf4j.LoggerFactory;
  * <li>
  * It maintains a map from (namenode, user) pairs to lease renewers.
  * The same {@link LeaseRenewer} instance is used for renewing lease
- * for all the {@link org.apache.hadoop.hdfs.DFSClient} to the same namenode and the same user.
+ * for all the {@link org.apache.hadoop.hdfs.DFSClient} to the same namenode and
+ * the same user.
  * </li>
  * <li>
  * Each renewer maintains a list of {@link org.apache.hadoop.hdfs.DFSClient}.
@@ -80,7 +81,7 @@ public class LeaseRenewer {
 
   /** Get a {@link LeaseRenewer} instance */
   public static LeaseRenewer getInstance(final String authority,
-      final UserGroupInformation ugi, final DFSClient dfsc) throws IOException {
+      final UserGroupInformation ugi, final DFSClient dfsc) {
     final LeaseRenewer r = Factory.INSTANCE.get(authority, ugi);
     r.addClient(dfsc);
     return r;
@@ -136,7 +137,7 @@ public class LeaseRenewer {
     }
 
     /** A map for per user per namenode renewers. */
-    private final Map<Key, LeaseRenewer> renewers = new HashMap<Key, LeaseRenewer>();
+    private final Map<Key, LeaseRenewer> renewers = new HashMap<>();
 
     /** Get a renewer. */
     private synchronized LeaseRenewer get(final String authority,
@@ -189,7 +190,7 @@ public class LeaseRenewer {
   private final Factory.Key factorykey;
 
   /** A list of clients corresponding to this renewer. */
-  private final List<DFSClient> dfsclients = new ArrayList<DFSClient>();
+  private final List<DFSClient> dfsclients = new ArrayList<>();
 
   /**
    * A stringified stack trace of the call stack when the Lease Renewer
@@ -404,7 +405,7 @@ public class LeaseRenewer {
   private void renew() throws IOException {
     final List<DFSClient> copies;
     synchronized(this) {
-      copies = new ArrayList<DFSClient>(dfsclients);
+      copies = new ArrayList<>(dfsclients);
     }
     //sort the client names for finding out repeated names.
     Collections.sort(copies, new Comparator<DFSClient>() {
@@ -414,8 +415,7 @@ public class LeaseRenewer {
       }
     });
     String previousName = "";
-    for(int i = 0; i < copies.size(); i++) {
+    for (final DFSClient c : copies) {
-      final DFSClient c = copies.get(i);
       //skip if current client name is the same as the previous name.
       if (!c.getClientName().equals(previousName)) {
         if (!c.renewLease()) {
@@ -470,7 +470,7 @@ public class LeaseRenewer {
               LOG.debug("Lease renewer daemon for " + clientsString()
                   + " with renew id " + id + " is not current");
             } else {
-               LOG.debug("Lease renewer daemon for " + clientsString()
+              LOG.debug("Lease renewer daemon for " + clientsString()
                   + " with renew id " + id + " expired");
             }
           }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/inotify/Event.java

@@ -34,7 +34,7 @@ import java.util.List;
 @InterfaceAudience.Public
 @InterfaceStability.Unstable
 public abstract class Event {
-  public static enum EventType {
+  public enum EventType {
     CREATE, CLOSE, APPEND, RENAME, METADATA, UNLINK, TRUNCATE
   }
 
@@ -98,8 +98,8 @@ public abstract class Event {
   @InterfaceAudience.Public
   public static class CreateEvent extends Event {
 
-    public static enum INodeType {
+    public enum INodeType {
-      FILE, DIRECTORY, SYMLINK;
+      FILE, DIRECTORY, SYMLINK
     }
 
     private INodeType iNodeType;
@@ -247,17 +247,21 @@ public abstract class Event {
     @InterfaceStability.Unstable
     public String toString() {
       StringBuilder content = new StringBuilder();
-      content.append("CreateEvent [INodeType=" + iNodeType + ", path=" + path
+      content.append("CreateEvent [INodeType=").append(iNodeType)
-          + ", ctime=" + ctime + ", replication=" + replication
+          .append(", path=").append(path)
-          + ", ownerName=" + ownerName + ", groupName=" + groupName
+          .append(", ctime=").append(ctime)
-          + ", perms=" + perms + ", ");
+          .append(", replication=").append(replication)
+          .append(", ownerName=").append(ownerName)
+          .append(", groupName=").append(groupName)
+          .append(", perms=").append(perms).append(", ");
 
       if (symlinkTarget != null) {
-        content.append("symlinkTarget=" + symlinkTarget + ", ");
+        content.append("symlinkTarget=").append(symlinkTarget).append(", ");
       }
 
-      content.append("overwrite=" + overwrite + ", defaultBlockSize="
+      content.append("overwrite=").append(overwrite)
-          + defaultBlockSize + "]");
+          .append(", defaultBlockSize=").append(defaultBlockSize)
+          .append("]");
       return content.toString();
     }
 
@@ -274,8 +278,8 @@ public abstract class Event {
   @InterfaceAudience.Public
   public static class MetadataUpdateEvent extends Event {
 
-    public static enum MetadataType {
+    public enum MetadataType {
-      TIMES, REPLICATION, OWNER, PERMS, ACLS, XATTRS;
+      TIMES, REPLICATION, OWNER, PERMS, ACLS, XATTRS
     }
 
     private String path;
@@ -434,28 +438,29 @@ public abstract class Event {
     @InterfaceStability.Unstable
     public String toString() {
       StringBuilder content = new StringBuilder();
-      content.append("MetadataUpdateEvent [path=" + path + ", metadataType="
+      content.append("MetadataUpdateEvent [path=").append(path)
-          + metadataType);
+          .append(", metadataType=").append(metadataType);
       switch (metadataType) {
       case TIMES:
-        content.append(", mtime=" + mtime + ", atime=" + atime);
+        content.append(", mtime=").append(mtime)
+            .append(", atime=").append(atime);
         break;
       case REPLICATION:
-        content.append(", replication=" + replication);
+        content.append(", replication=").append(replication);
         break;
       case OWNER:
-        content.append(", ownerName=" + ownerName
+        content.append(", ownerName=").append(ownerName)
-            + ", groupName=" + groupName);
+            .append(", groupName=").append(groupName);
         break;
       case PERMS:
-        content.append(", perms=" + perms);
+        content.append(", perms=").append(perms);
         break;
       case ACLS:
-        content.append(", acls=" + acls);
+        content.append(", acls=").append(acls);
         break;
       case XATTRS:
-        content.append(", xAttrs=" + xAttrs + ", xAttrsRemoved="
+        content.append(", xAttrs=").append(xAttrs)
-            + xAttrsRemoved);
+            .append(", xAttrsRemoved=").append(xAttrsRemoved);
         break;
       default:
         break;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/net/Peer.java

@@ -34,24 +34,24 @@ public interface Peer extends Closeable {
    * @return                The input stream channel associated with this
    *                        peer, or null if it has none.
    */
-  public ReadableByteChannel getInputStreamChannel();
+  ReadableByteChannel getInputStreamChannel();
 
   /**
    * Set the read timeout on this peer.
    *
    * @param timeoutMs       The timeout in milliseconds.
    */
-  public void setReadTimeout(int timeoutMs) throws IOException;
+  void setReadTimeout(int timeoutMs) throws IOException;
 
   /**
    * @return                The receive buffer size.
    */
-  public int getReceiveBufferSize() throws IOException;
+  int getReceiveBufferSize() throws IOException;
 
   /**
    * @return                True if TCP_NODELAY is turned on.
    */
-  public boolean getTcpNoDelay() throws IOException;
+  boolean getTcpNoDelay() throws IOException;
 
   /**
    * Set the write timeout on this peer.
@@ -61,57 +61,57 @@ public interface Peer extends Closeable {
    *
    * @param timeoutMs       The timeout in milliseconds.
    */
-  public void setWriteTimeout(int timeoutMs) throws IOException;
+  void setWriteTimeout(int timeoutMs) throws IOException;
 
   /**
    * @return                true only if the peer is closed.
    */
-  public boolean isClosed();
+  boolean isClosed();
 
   /**
    * Close the peer.
    *
    * It's safe to re-close a Peer that is already closed.
    */
-  public void close() throws IOException;
+  void close() throws IOException;
 
   /**
    * @return               A string representing the remote end of our
    *                       connection to the peer.
    */
-  public String getRemoteAddressString();
+  String getRemoteAddressString();
 
   /**
    * @return               A string representing the local end of our
    *                       connection to the peer.
    */
-  public String getLocalAddressString();
+  String getLocalAddressString();
 
   /**
    * @return               An InputStream associated with the Peer.
    *                       This InputStream will be valid until you close
    *                       this peer with Peer#close.
    */
-  public InputStream getInputStream() throws IOException;
+  InputStream getInputStream() throws IOException;
 
   /**
    * @return               An OutputStream associated with the Peer.
    *                       This OutputStream will be valid until you close
    *                       this peer with Peer#close.
    */
-  public OutputStream getOutputStream() throws IOException;
+  OutputStream getOutputStream() throws IOException;
 
   /**
    * @return               True if the peer resides on the same
    *                       computer as we.
    */
-  public boolean isLocal();
+  boolean isLocal();
 
   /**
    * @return               The DomainSocket associated with the current
    *                       peer, or null if there is none.
    */
-  public DomainSocket getDomainSocket();
+  DomainSocket getDomainSocket();
 
   /**
    * Return true if the channel is secure.
@@ -119,5 +119,5 @@ public interface Peer extends Closeable {
    * @return               True if our channel to this peer is not
    *                       susceptible to man-in-the-middle attacks.
    */
-  public boolean hasSecureChannel();
+  boolean hasSecureChannel();
 }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/Block.java

@@ -25,6 +25,8 @@ import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.io.*;
 
+import javax.annotation.Nonnull;
+
 /**************************************************
  * A Block is a Hadoop FS primitive, identified by a
  * long.
@@ -36,12 +38,10 @@ public class Block implements Writable, Comparable<Block> {
   public static final String BLOCK_FILE_PREFIX = "blk_";
   public static final String METADATA_EXTENSION = ".meta";
   static {                                      // register a ctor
-    WritableFactories.setFactory
+    WritableFactories.setFactory(Block.class, new WritableFactory() {
-      (Block.class,
+      @Override
-       new WritableFactory() {
+      public Writable newInstance() { return new Block(); }
-         @Override
+    });
-         public Writable newInstance() { return new Block(); }
-       });
   }
 
   public static final Pattern blockFilePattern = Pattern
@@ -208,20 +208,14 @@ public class Block implements Writable, Comparable<Block> {
   }
 
   @Override // Comparable
-  public int compareTo(Block b) {
+  public int compareTo(@Nonnull Block b) {
     return blockId < b.blockId ? -1 :
-           blockId > b.blockId ? 1 : 0;
+        blockId > b.blockId ? 1 : 0;
   }
 
   @Override // Object
   public boolean equals(Object o) {
-    if (this == o) {
+    return this == o || o instanceof Block && compareTo((Block) o) == 0;
-      return true;
-    }
-    if (!(o instanceof Block)) {
-      return false;
-    }
-    return compareTo((Block)o) == 0;
   }
 
   /**
@@ -230,9 +224,10 @@ public class Block implements Writable, Comparable<Block> {
    */
   public static boolean matchingIdAndGenStamp(Block a, Block b) {
     if (a == b) return true; // same block, or both null
-    if (a == null || b == null) return false; // only one null
+    // only one null
-    return a.blockId == b.blockId &&
+    return !(a == null || b == null) &&
-           a.generationStamp == b.generationStamp;
+        a.blockId == b.blockId &&
+        a.generationStamp == b.generationStamp;
   }
 
   @Override // Object

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/BlockStoragePolicy.java

@@ -79,7 +79,7 @@ public class BlockStoragePolicy implements BlockStoragePolicySpi {
    * @return a list of {@link StorageType}s for storing the replicas of a block.
    */
   public List<StorageType> chooseStorageTypes(final short replication) {
-    final List<StorageType> types = new LinkedList<StorageType>();
+    final List<StorageType> types = new LinkedList<>();
     int i = 0, j = 0;
 
     // Do not return transient storage types. We will not have accurate
@@ -136,11 +136,11 @@ public class BlockStoragePolicy implements BlockStoragePolicySpi {
       final Iterable<StorageType> chosen,
       final EnumSet<StorageType> unavailables,
       final boolean isNewBlock) {
-    final List<StorageType> excess = new LinkedList<StorageType>();
+    final List<StorageType> excess = new LinkedList<>();
     final List<StorageType> storageTypes = chooseStorageTypes(
         replication, chosen, excess);
     final int expectedSize = storageTypes.size() - excess.size();
-    final List<StorageType> removed = new LinkedList<StorageType>();
+    final List<StorageType> removed = new LinkedList<>();
     for(int i = storageTypes.size() - 1; i >= 0; i--) {
       // replace/remove unavailable storage types.
       final StorageType t = storageTypes.get(i);
@@ -195,7 +195,7 @@ public class BlockStoragePolicy implements BlockStoragePolicySpi {
   public List<StorageType> chooseExcess(final short replication,
       final Iterable<StorageType> chosen) {
     final List<StorageType> types = chooseStorageTypes(replication);
-    final List<StorageType> excess = new LinkedList<StorageType>();
+    final List<StorageType> excess = new LinkedList<>();
     diff(types, chosen, excess);
     return excess;
   }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/CacheDirectiveEntry.java

@@ -42,4 +42,4 @@ public class CacheDirectiveEntry {
   public CacheDirectiveStats getStats() {
     return stats;
   }
-};
+}

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/CacheDirectiveInfo.java

@@ -350,9 +350,8 @@ public class CacheDirectiveInfo {
     }
     if (expiration != null) {
       builder.append(prefix).append("expiration: ").append(expiration);
-      prefix = ", ";
     }
     builder.append("}");
     return builder.toString();
   }
-};
+}

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/CacheDirectiveIterator.java

@@ -92,9 +92,8 @@ public class CacheDirectiveIterator
   @Override
   public BatchedEntries<CacheDirectiveEntry> makeRequest(Long prevKey)
       throws IOException {
-    BatchedEntries<CacheDirectiveEntry> entries = null;
+    BatchedEntries<CacheDirectiveEntry> entries;
-    TraceScope scope = tracer.newScope("listCacheDirectives");
+    try (TraceScope ignored = tracer.newScope("listCacheDirectives")) {
-    try {
       entries = namenode.listCacheDirectives(prevKey, filter);
     } catch (IOException e) {
       if (e.getMessage().contains("Filtering by ID is unsupported")) {
@@ -105,9 +104,9 @@ public class CacheDirectiveIterator
         // This is somewhat brittle, since it depends on directives being
         // returned in order of ascending ID.
         entries = namenode.listCacheDirectives(id - 1, filter);
-        for (int i=0; i<entries.size(); i++) {
+        for (int i = 0; i < entries.size(); i++) {
           CacheDirectiveEntry entry = entries.get(i);
-          if (entry.getInfo().getId().equals((Long)id)) {
+          if (entry.getInfo().getId().equals(id)) {
             return new SingleEntry(entry);
           }
         }
@@ -115,8 +114,6 @@ public class CacheDirectiveIterator
             "Did not find requested id " + id);
       }
       throw e;
-    } finally {
-      scope.close();
     }
     Preconditions.checkNotNull(entries);
     return entries;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/CacheDirectiveStats.java

@@ -156,14 +156,10 @@ public class CacheDirectiveStats {
 
   @Override
   public String toString() {
-    StringBuilder builder = new StringBuilder();
+    return "{" + "bytesNeeded: " + bytesNeeded + ", "
-    builder.append("{");
+        + "bytesCached: " + bytesCached + ", "
-    builder.append("bytesNeeded: ").append(bytesNeeded);
+        + "filesNeeded: " + filesNeeded + ", "
-    builder.append(", ").append("bytesCached: ").append(bytesCached);
+        + "filesCached: " + filesCached + ", "
-    builder.append(", ").append("filesNeeded: ").append(filesNeeded);
+        + "hasExpired: " + hasExpired + "}";
-    builder.append(", ").append("filesCached: ").append(filesCached);
-    builder.append(", ").append("hasExpired: ").append(hasExpired);
-    builder.append("}");
-    return builder.toString();
   }
-};
+}

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/CachePoolInfo.java

@@ -155,15 +155,13 @@ public class CachePoolInfo {
   }
 
   public String toString() {
-    return new StringBuilder().append("{").
+    return "{" + "poolName:" + poolName
-      append("poolName:").append(poolName).
+        + ", ownerName:" + ownerName
-      append(", ownerName:").append(ownerName).
+        + ", groupName:" + groupName
-      append(", groupName:").append(groupName).
+        + ", mode:"
-      append(", mode:").append((mode == null) ? "null" :
+        + ((mode == null) ? "null" : String.format("0%03o", mode.toShort()))
-          String.format("0%03o", mode.toShort())).
+        + ", limit:" + limit
-      append(", limit:").append(limit).
+        + ", maxRelativeExpiryMs:" + maxRelativeExpiryMs + "}";
-      append(", maxRelativeExpiryMs:").append(maxRelativeExpiryMs).
-      append("}").toString();
   }
 
   @Override

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/CachePoolIterator.java

@@ -47,11 +47,8 @@ public class CachePoolIterator
   @Override
   public BatchedEntries<CachePoolEntry> makeRequest(String prevKey)
       throws IOException {
-    TraceScope scope = tracer.newScope("listCachePools");
+    try (TraceScope ignored = tracer.newScope("listCachePools")) {
-    try {
       return namenode.listCachePools(prevKey);
-    } finally {
-      scope.close();
     }
   }
 

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/CachePoolStats.java

@@ -66,7 +66,7 @@ public class CachePoolStats {
       return new CachePoolStats(bytesNeeded, bytesCached, bytesOverlimit,
           filesNeeded, filesCached);
     }
-  };
+  }
 
   private final long bytesNeeded;
   private final long bytesCached;
@@ -104,12 +104,10 @@ public class CachePoolStats {
   }
 
   public String toString() {
-    return new StringBuilder().append("{").
+    return "{" + "bytesNeeded:" + bytesNeeded
-      append("bytesNeeded:").append(bytesNeeded).
+        + ", bytesCached:" + bytesCached
-      append(", bytesCached:").append(bytesCached).
+        + ", bytesOverlimit:" + bytesOverlimit
-      append(", bytesOverlimit:").append(bytesOverlimit).
+        + ", filesNeeded:" + filesNeeded
-      append(", filesNeeded:").append(filesNeeded).
+        + ", filesCached:" + filesCached + "}";
-      append(", filesCached:").append(filesCached).
-      append("}").toString();
   }
 }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/ClientDatanodeProtocol.java

@@ -60,7 +60,7 @@ public interface ClientDatanodeProtocol {
    * 9 is the last version id when this class was used for protocols
    *  serialization. DO not update this version any further.
    */
-  public static final long versionID = 9L;
+  long versionID = 9L;
 
   /** Return the visible length of a replica. */
   long getReplicaVisibleLength(ExtendedBlock b) throws IOException;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/ClientProtocol.java

@@ -47,6 +47,7 @@ import org.apache.hadoop.io.EnumSetWritable;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.io.retry.AtMostOnce;
 import org.apache.hadoop.io.retry.Idempotent;
+import org.apache.hadoop.security.AccessControlException;
 import org.apache.hadoop.security.KerberosInfo;
 import org.apache.hadoop.security.token.Token;
 import org.apache.hadoop.security.token.TokenInfo;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/DSQuotaExceededException.java

@@ -42,8 +42,10 @@ public class DSQuotaExceededException extends QuotaExceededException {
     String msg = super.getMessage();
     if (msg == null) {
       return "The DiskSpace quota" + (pathName==null?"": " of " + pathName)
-          + " is exceeded: quota = " + quota + " B = " + long2String(quota, "B", 2)
+          + " is exceeded: quota = " + quota
-          + " but diskspace consumed = " + count + " B = " + long2String(count, "B", 2);
+          + " B = " + long2String(quota, "B", 2)
+          + " but diskspace consumed = " + count
+          + " B = " + long2String(count, "B", 2);
     } else {
       return msg;
     }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/DatanodeID.java

@@ -233,14 +233,10 @@ public class DatanodeID implements Comparable<DatanodeID> {
 
   @Override
   public boolean equals(Object to) {
-    if (this == to) {
+    return this == to ||
-      return true;
+        (to instanceof DatanodeID &&
-    }
+            getXferAddr().equals(((DatanodeID) to).getXferAddr()) &&
-    if (!(to instanceof DatanodeID)) {
+            datanodeUuid.equals(((DatanodeID) to).getDatanodeUuid()));
-      return false;
-    }
-    return (getXferAddr().equals(((DatanodeID)to).getXferAddr()) &&
-        datanodeUuid.equals(((DatanodeID)to).getDatanodeUuid()));
   }
 
   @Override

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/DatanodeInfo.java

@@ -52,7 +52,7 @@ public class DatanodeInfo extends DatanodeID implements Node {
   private int xceiverCount;
   private String location = NetworkTopology.DEFAULT_RACK;
   private String softwareVersion;
-  private List<String> dependentHostNames = new LinkedList<String>();
+  private List<String> dependentHostNames = new LinkedList<>();
   private String upgradeDomain;
 
   // Datanode administrative states
@@ -358,18 +358,18 @@ public class DatanodeInfo extends DatanodeID implements Node {
     float cacheRemainingPercent = getCacheRemainingPercent();
     String lookupName = NetUtils.getHostNameOfIP(getName());
 
-    buffer.append("Name: "+ getName());
+    buffer.append("Name: ").append(getName());
     if (lookupName != null) {
-      buffer.append(" (" + lookupName + ")");
+      buffer.append(" (").append(lookupName).append(")");
     }
     buffer.append("\n");
-    buffer.append("Hostname: " + getHostName() + "\n");
+    buffer.append("Hostname: ").append(getHostName()).append("\n");
 
     if (!NetworkTopology.DEFAULT_RACK.equals(location)) {
-      buffer.append("Rack: "+location+"\n");
+      buffer.append("Rack: ").append(location).append("\n");
     }
     if (upgradeDomain != null) {
-      buffer.append("Upgrade domain: "+ upgradeDomain +"\n");
+      buffer.append("Upgrade domain: ").append(upgradeDomain).append("\n");
     }
     buffer.append("Decommission Status : ");
     if (isDecommissioned()) {
@@ -379,19 +379,30 @@ public class DatanodeInfo extends DatanodeID implements Node {
     } else {
       buffer.append("Normal\n");
     }
-    buffer.append("Configured Capacity: "+c+" ("+StringUtils.byteDesc(c)+")"+"\n");
+    buffer.append("Configured Capacity: ").append(c).append(" (")
-    buffer.append("DFS Used: "+u+" ("+StringUtils.byteDesc(u)+")"+"\n");
+        .append(StringUtils.byteDesc(c)).append(")").append("\n");
-    buffer.append("Non DFS Used: "+nonDFSUsed+" ("+StringUtils.byteDesc(nonDFSUsed)+")"+"\n");
+    buffer.append("DFS Used: ").append(u).append(" (")
-    buffer.append("DFS Remaining: " +r+ " ("+StringUtils.byteDesc(r)+")"+"\n");
+        .append(StringUtils.byteDesc(u)).append(")").append("\n");
-    buffer.append("DFS Used%: "+percent2String(usedPercent) + "\n");
+    buffer.append("Non DFS Used: ").append(nonDFSUsed).append(" (")
-    buffer.append("DFS Remaining%: "+percent2String(remainingPercent) + "\n");
+        .append(StringUtils.byteDesc(nonDFSUsed)).append(")").append("\n");
-    buffer.append("Configured Cache Capacity: "+cc+" ("+StringUtils.byteDesc(cc)+")"+"\n");
+    buffer.append("DFS Remaining: ").append(r).append(" (")
-    buffer.append("Cache Used: "+cu+" ("+StringUtils.byteDesc(cu)+")"+"\n");
+        .append(StringUtils.byteDesc(r)).append(")").append("\n");
-    buffer.append("Cache Remaining: " +cr+ " ("+StringUtils.byteDesc(cr)+")"+"\n");
+    buffer.append("DFS Used%: ").append(percent2String(usedPercent))
-    buffer.append("Cache Used%: "+percent2String(cacheUsedPercent) + "\n");
+        .append("\n");
-    buffer.append("Cache Remaining%: "+percent2String(cacheRemainingPercent) + "\n");
+    buffer.append("DFS Remaining%: ").append(percent2String(remainingPercent))
-    buffer.append("Xceivers: "+getXceiverCount()+"\n");
+        .append("\n");
-    buffer.append("Last contact: "+new Date(lastUpdate)+"\n");
+    buffer.append("Configured Cache Capacity: ").append(cc).append(" (")
+        .append(StringUtils.byteDesc(cc)).append(")").append("\n");
+    buffer.append("Cache Used: ").append(cu).append(" (")
+        .append(StringUtils.byteDesc(cu)).append(")").append("\n");
+    buffer.append("Cache Remaining: ").append(cr).append(" (")
+        .append(StringUtils.byteDesc(cr)).append(")").append("\n");
+    buffer.append("Cache Used%: ").append(percent2String(cacheUsedPercent))
+        .append("\n");
+    buffer.append("Cache Remaining%: ")
+        .append(percent2String(cacheRemainingPercent)).append("\n");
+    buffer.append("Xceivers: ").append(getXceiverCount()).append("\n");
+    buffer.append("Last contact: ").append(new Date(lastUpdate)).append("\n");
     return buffer.toString();
   }
 
@@ -408,10 +419,10 @@ public class DatanodeInfo extends DatanodeID implements Node {
     float cacheUsedPercent = getCacheUsedPercent();
     buffer.append(getName());
     if (!NetworkTopology.DEFAULT_RACK.equals(location)) {
-      buffer.append(" "+location);
+      buffer.append(" ").append(location);
     }
     if (upgradeDomain != null) {
-      buffer.append(" " + upgradeDomain);
+      buffer.append(" ").append(upgradeDomain);
     }
     if (isDecommissioned()) {
       buffer.append(" DD");
@@ -420,15 +431,21 @@ public class DatanodeInfo extends DatanodeID implements Node {
     } else {
       buffer.append(" IN");
     }
-    buffer.append(" " + c + "(" + StringUtils.byteDesc(c)+")");
+    buffer.append(" ").append(c).append("(").append(StringUtils.byteDesc(c))
-    buffer.append(" " + u + "(" + StringUtils.byteDesc(u)+")");
+        .append(")");
-    buffer.append(" " + percent2String(usedPercent));
+    buffer.append(" ").append(u).append("(").append(StringUtils.byteDesc(u))
-    buffer.append(" " + r + "(" + StringUtils.byteDesc(r)+")");
+        .append(")");
-    buffer.append(" " + cc + "(" + StringUtils.byteDesc(cc)+")");
+    buffer.append(" ").append(percent2String(usedPercent));
-    buffer.append(" " + cu + "(" + StringUtils.byteDesc(cu)+")");
+    buffer.append(" ").append(r).append("(").append(StringUtils.byteDesc(r))
-    buffer.append(" " + percent2String(cacheUsedPercent));
+        .append(")");
-    buffer.append(" " + cr + "(" + StringUtils.byteDesc(cr)+")");
+    buffer.append(" ").append(cc).append("(").append(StringUtils.byteDesc(cc))
-    buffer.append(" " + new Date(lastUpdate));
+        .append(")");
+    buffer.append(" ").append(cu).append("(").append(StringUtils.byteDesc(cu))
+        .append(")");
+    buffer.append(" ").append(percent2String(cacheUsedPercent));
+    buffer.append(" ").append(cr).append("(").append(StringUtils.byteDesc(cr))
+        .append(")");
+    buffer.append(" ").append(new Date(lastUpdate));
     return buffer.toString();
   }
 

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/DatanodeInfoWithStorage.java

@@ -20,7 +20,6 @@ package org.apache.hadoop.hdfs.protocol;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.fs.StorageType;
-import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 
 @InterfaceAudience.Private
 @InterfaceStability.Evolving
@@ -29,7 +28,7 @@ public class DatanodeInfoWithStorage extends DatanodeInfo {
   private final StorageType storageType;
 
   public DatanodeInfoWithStorage(DatanodeInfo from, String storageID,
-                                 StorageType storageType) {
+      StorageType storageType) {
     super(from);
     this.storageID = storageID;
     this.storageType = storageType;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/DatanodeLocalInfo.java

@@ -55,10 +55,8 @@ public class DatanodeLocalInfo {
 
   /** A formatted string for printing the status of the DataNode. */
   public String getDatanodeLocalReport() {
-    StringBuilder buffer = new StringBuilder();
+    return ("Uptime: " + getUptime())
-    buffer.append("Uptime: " + getUptime());
+        + ", Software version: " + getSoftwareVersion()
-    buffer.append(", Software version: " + getSoftwareVersion());
+        + ", Config version: " + getConfigVersion();
-    buffer.append(", Config version: " + getConfigVersion());
-    return buffer.toString();
   }
 }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/EncryptionZoneIterator.java

@@ -39,7 +39,7 @@ public class EncryptionZoneIterator
   private final Tracer tracer;
 
   public EncryptionZoneIterator(ClientProtocol namenode, Tracer tracer) {
-    super(Long.valueOf(0));
+    super((long) 0);
     this.namenode = namenode;
     this.tracer = tracer;
   }
@@ -47,11 +47,8 @@ public class EncryptionZoneIterator
   @Override
   public BatchedEntries<EncryptionZone> makeRequest(Long prevId)
       throws IOException {
-    TraceScope scope = tracer.newScope("listEncryptionZones");
+    try (TraceScope ignored = tracer.newScope("listEncryptionZones")) {
-    try {
       return namenode.listEncryptionZones(prevId);
-    } finally {
-      scope.close();
     }
   }
 

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/HdfsFileStatus.java

@@ -33,7 +33,8 @@ import org.apache.hadoop.hdfs.DFSUtilClient;
 @InterfaceStability.Evolving
 public class HdfsFileStatus {
 
-  private final byte[] path;  // local name of the inode that's encoded in java UTF8
+  // local name of the inode that's encoded in java UTF8
+  private final byte[] path;
   private final byte[] symlink; // symlink target encoded in java UTF8 or null
   private final long length;
   private final boolean isdir;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/LastBlockWithStatus.java

@@ -31,7 +31,8 @@ public class LastBlockWithStatus {
 
   private final HdfsFileStatus fileStatus;
 
-  public LastBlockWithStatus(LocatedBlock lastBlock, HdfsFileStatus fileStatus) {
+  public LastBlockWithStatus(LocatedBlock lastBlock,
+      HdfsFileStatus fileStatus) {
     this.lastBlock = lastBlock;
     this.fileStatus = fileStatus;
   }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/LocatedBlock.java

@@ -65,13 +65,13 @@ public class LocatedBlock {
   }
 
   public LocatedBlock(ExtendedBlock b, DatanodeInfo[] locs,
-                      String[] storageIDs, StorageType[] storageTypes) {
+      String[] storageIDs, StorageType[] storageTypes) {
     this(b, locs, storageIDs, storageTypes, -1, false, EMPTY_LOCS);
   }
 
   public LocatedBlock(ExtendedBlock b, DatanodeInfo[] locs, String[] storageIDs,
-                      StorageType[] storageTypes, long startOffset,
+      StorageType[] storageTypes, long startOffset,
-                      boolean corrupt, DatanodeInfo[] cachedLocs) {
+      boolean corrupt, DatanodeInfo[] cachedLocs) {
     this.b = b;
     this.offset = startOffset;
     this.corrupt = corrupt;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/LocatedBlocks.java

@@ -32,7 +32,8 @@ import org.apache.hadoop.fs.FileEncryptionInfo;
 @InterfaceStability.Evolving
 public class LocatedBlocks {
   private final long fileLength;
-  private final List<LocatedBlock> blocks; // array of blocks with prioritized locations
+  // array of blocks with prioritized locations
+  private final List<LocatedBlock> blocks;
   private final boolean underConstruction;
   private final LocatedBlock lastLocatedBlock;
   private final boolean isLastBlockComplete;
@@ -123,22 +124,22 @@ public class LocatedBlocks {
     key.setStartOffset(offset);
     key.getBlock().setNumBytes(1);
     Comparator<LocatedBlock> comp =
-      new Comparator<LocatedBlock>() {
+        new Comparator<LocatedBlock>() {
-        // Returns 0 iff a is inside b or b is inside a
+          // Returns 0 iff a is inside b or b is inside a
-        @Override
+          @Override
-        public int compare(LocatedBlock a, LocatedBlock b) {
+          public int compare(LocatedBlock a, LocatedBlock b) {
-          long aBeg = a.getStartOffset();
+            long aBeg = a.getStartOffset();
-          long bBeg = b.getStartOffset();
+            long bBeg = b.getStartOffset();
-          long aEnd = aBeg + a.getBlockSize();
+            long aEnd = aBeg + a.getBlockSize();
-          long bEnd = bBeg + b.getBlockSize();
+            long bEnd = bBeg + b.getBlockSize();
-          if(aBeg <= bBeg && bEnd <= aEnd
+            if(aBeg <= bBeg && bEnd <= aEnd
-              || bBeg <= aBeg && aEnd <= bEnd)
+                || bBeg <= aBeg && aEnd <= bEnd)
-            return 0; // one of the blocks is inside the other
+              return 0; // one of the blocks is inside the other
-          if(aBeg < bBeg)
+            if(aBeg < bBeg)
-            return -1; // a's left bound is to the left of the b's
+              return -1; // a's left bound is to the left of the b's
-          return 1;
+            return 1;
-        }
+          }
-      };
+        };
     return Collections.binarySearch(blocks, key, comp);
   }
 
@@ -176,14 +177,10 @@ public class LocatedBlocks {
 
   @Override
   public String toString() {
-    final StringBuilder b = new StringBuilder(getClass().getSimpleName());
+    return getClass().getSimpleName() + "{" + "\n  fileLength=" + fileLength
-    b.append("{")
+        + "\n  underConstruction=" + underConstruction
-     .append("\n  fileLength=").append(fileLength)
+        + "\n  blocks=" + blocks
-     .append("\n  underConstruction=").append(underConstruction)
+        + "\n  lastLocatedBlock=" + lastLocatedBlock
-     .append("\n  blocks=").append(blocks)
+        + "\n  isLastBlockComplete=" + isLastBlockComplete + "}";
-     .append("\n  lastLocatedBlock=").append(lastLocatedBlock)
-     .append("\n  isLastBlockComplete=").append(isLastBlockComplete)
-     .append("}");
-    return b.toString();
   }
 }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/NSQuotaExceededException.java

@@ -43,7 +43,7 @@ public final class NSQuotaExceededException extends QuotaExceededException {
     String msg = super.getMessage();
     if (msg == null) {
       msg = "The NameSpace quota (directories and files)" +
-      (pathName==null?"":(" of directory " + pathName)) +
+          (pathName==null?"":(" of directory " + pathName)) +
           " is exceeded: quota=" + quota + " file count=" + count;
 
       if (prefix != null) {

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/RollingUpgradeInfo.java

@@ -64,7 +64,6 @@ public class RollingUpgradeInfo extends RollingUpgradeStatus {
 
   /**
    * Finalize the upgrade if not already finalized
-   * @param finalizeTime
    */
   public void finalize(long finalizeTime) {
     if (finalizeTime != 0) {
@@ -99,8 +98,11 @@ public class RollingUpgradeInfo extends RollingUpgradeStatus {
   @Override
   public String toString() {
     return super.toString()
-      +  "\n     Start Time: " + (startTime == 0? "<NOT STARTED>": timestamp2String(startTime))
+        +  "\n     Start Time: "
-      +  "\n  Finalize Time: " + (finalizeTime == 0? "<NOT FINALIZED>": timestamp2String(finalizeTime));
+        + (startTime == 0 ? "<NOT STARTED>" : timestamp2String(startTime))
+        +  "\n  Finalize Time: "
+        + (finalizeTime == 0 ? "<NOT FINALIZED>" :
+        timestamp2String(finalizeTime));
   }
 
   private static String timestamp2String(long timestamp) {

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/SnapshotDiffReport.java

@@ -49,7 +49,7 @@ public class SnapshotDiffReport {
 
     private final String label;
 
-    private DiffType(String label) {
+    DiffType(String label) {
       this.label = label;
     }
 
@@ -69,7 +69,7 @@ public class SnapshotDiffReport {
       }
       return null;
     }
-  };
+  }
 
   /**
    * Representing the full path and diff type of a file/directory where changes
@@ -205,10 +205,11 @@ public class SnapshotDiffReport {
         "current directory" : "snapshot " + fromSnapshot;
     String to = toSnapshot == null || toSnapshot.isEmpty() ? "current directory"
         : "snapshot " + toSnapshot;
-    str.append("Difference between " + from + " and " + to
+    str.append("Difference between ").append(from).append(" and ").append(to)
-        + " under directory " + snapshotRoot + ":" + LINE_SEPARATOR);
+        .append(" under directory ").append(snapshotRoot).append(":")
+        .append(LINE_SEPARATOR);
     for (DiffReportEntry entry : diffList) {
-      str.append(entry.toString() + LINE_SEPARATOR);
+      str.append(entry.toString()).append(LINE_SEPARATOR);
     }
     return str.toString();
   }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/SnapshottableDirectoryStatus.java

@@ -31,17 +31,18 @@ import org.apache.hadoop.hdfs.DFSUtilClient;
  */
 public class SnapshottableDirectoryStatus {
   /** Compare the statuses by full paths. */
-  public static final Comparator<SnapshottableDirectoryStatus> COMPARATOR
+  public static final Comparator<SnapshottableDirectoryStatus> COMPARATOR =
-      = new Comparator<SnapshottableDirectoryStatus>() {
+      new Comparator<SnapshottableDirectoryStatus>() {
-    @Override
+        @Override
-    public int compare(SnapshottableDirectoryStatus left,
+        public int compare(SnapshottableDirectoryStatus left,
-                       SnapshottableDirectoryStatus right) {
+            SnapshottableDirectoryStatus right) {
-      int d = DFSUtilClient.compareBytes(left.parentFullPath, right.parentFullPath);
+          int d = DFSUtilClient.compareBytes(left.parentFullPath,
-      return d != 0? d
+              right.parentFullPath);
-          : DFSUtilClient.compareBytes(left.dirStatus.getLocalNameInBytes(),
+          return d != 0? d
+              : DFSUtilClient.compareBytes(left.dirStatus.getLocalNameInBytes(),
               right.dirStatus.getLocalNameInBytes());
-    }
+        }
-  };
+      };
 
   /** Basic information of the snapshottable directory */
   private final HdfsFileStatus dirStatus;
@@ -134,18 +135,16 @@ public class SnapshottableDirectoryStatus {
       maxSnapshotQuota = maxLength(maxSnapshotQuota, status.snapshotQuota);
     }
 
-    StringBuilder fmt = new StringBuilder();
+    String lineFormat = "%s%s " // permission string
-    fmt.append("%s%s "); // permission string
+        + "%"  + maxRepl  + "s "
-    fmt.append("%"  + maxRepl  + "s ");
+        + (maxOwner > 0 ? "%-" + maxOwner + "s " : "%s")
-    fmt.append((maxOwner > 0) ? "%-" + maxOwner + "s " : "%s");
+        + (maxGroup > 0 ? "%-" + maxGroup + "s " : "%s")
-    fmt.append((maxGroup > 0) ? "%-" + maxGroup + "s " : "%s");
+        + "%"  + maxLen   + "s "
-    fmt.append("%"  + maxLen   + "s ");
+        + "%s " // mod time
-    fmt.append("%s "); // mod time
+        + "%"  + maxSnapshotNum  + "s "
-    fmt.append("%"  + maxSnapshotNum  + "s ");
+        + "%"  + maxSnapshotQuota  + "s "
-    fmt.append("%"  + maxSnapshotQuota  + "s ");
+        + "%s"; // path
-    fmt.append("%s"); // path
 
-    String lineFormat = fmt.toString();
     SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm");
 
     for (SnapshottableDirectoryStatus status : stats) {

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/UnresolvedPathException.java

@@ -18,8 +18,6 @@
 
 package org.apache.hadoop.hdfs.protocol;
 
-import java.io.IOException;
-
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.fs.UnresolvedLinkException;
@@ -55,7 +53,7 @@ public final class UnresolvedPathException extends UnresolvedLinkException {
   /**
    * Return a path with the link resolved with the target.
    */
-  public Path getResolvedPath() throws IOException {
+  public Path getResolvedPath() {
     // If the path is absolute we cam throw out the preceding part and
     // just append the remainder to the target, otherwise append each
     // piece to resolve the link in path.
@@ -76,12 +74,6 @@ public final class UnresolvedPathException extends UnresolvedLinkException {
     if (msg != null) {
       return msg;
     }
-    String myMsg = "Unresolved path " + path;
+    return getResolvedPath().toString();
-    try {
-      return getResolvedPath().toString();
-    } catch (IOException e) {
-      // Ignore
-    }
-    return myMsg;
   }
 }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/DataTransferProtoUtil.java

@@ -65,7 +65,9 @@ public abstract class DataTransferProtoUtil {
   }
 
   public static DataChecksum fromProto(ChecksumProto proto) {
-    if (proto == null) return null;
+    if (proto == null) {
+      return null;
+    }
 
     int bytesPerChecksum = proto.getBytesPerChecksum();
     DataChecksum.Type type = PBHelperClient.convert(proto.getType());
@@ -74,19 +76,17 @@ public abstract class DataTransferProtoUtil {
 
   static ClientOperationHeaderProto buildClientHeader(ExtendedBlock blk,
       String client, Token<BlockTokenIdentifier> blockToken) {
-    ClientOperationHeaderProto header =
+    return ClientOperationHeaderProto.newBuilder()
-      ClientOperationHeaderProto.newBuilder()
+      .setBaseHeader(buildBaseHeader(blk, blockToken))
-        .setBaseHeader(buildBaseHeader(blk, blockToken))
+      .setClientName(client)
-        .setClientName(client)
+      .build();
-        .build();
-    return header;
   }
 
   static BaseHeaderProto buildBaseHeader(ExtendedBlock blk,
       Token<BlockTokenIdentifier> blockToken) {
     BaseHeaderProto.Builder builder =  BaseHeaderProto.newBuilder()
-      .setBlock(PBHelperClient.convert(blk))
+        .setBlock(PBHelperClient.convert(blk))
-      .setToken(PBHelperClient.convert(blockToken));
+        .setToken(PBHelperClient.convert(blockToken));
     SpanId spanId = Tracer.getCurrentSpanId();
     if (spanId.isValid()) {
       builder.setTraceInfo(DataTransferTraceInfoProto.newBuilder()

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/DataTransferProtocol.java

@@ -39,7 +39,7 @@ import org.slf4j.LoggerFactory;
 @InterfaceAudience.Private
 @InterfaceStability.Evolving
 public interface DataTransferProtocol {
-  public static final Logger LOG = LoggerFactory.getLogger(DataTransferProtocol.class);
+  Logger LOG = LoggerFactory.getLogger(DataTransferProtocol.class);
 
   /** Version for data transfers between clients and datanodes
    * This should change when serialization of DatanodeInfo, not just
@@ -49,7 +49,7 @@ public interface DataTransferProtocol {
    * Version 28:
    *    Declare methods in DataTransferProtocol interface.
    */
-  public static final int DATA_TRANSFER_VERSION = 28;
+  int DATA_TRANSFER_VERSION = 28;
 
   /**
    * Read a block.
@@ -63,7 +63,7 @@ public interface DataTransferProtocol {
    *        checksums
    * @param cachingStrategy  The caching strategy to use.
    */
-  public void readBlock(final ExtendedBlock blk,
+  void readBlock(final ExtendedBlock blk,
       final Token<BlockTokenIdentifier> blockToken,
       final String clientName,
       final long blockOffset,
@@ -96,7 +96,7 @@ public interface DataTransferProtocol {
    * @param pinning whether to pin the block, so Balancer won't move it.
    * @param targetPinnings whether to pin the block on target datanode
    */
-  public void writeBlock(final ExtendedBlock blk,
+  void writeBlock(final ExtendedBlock blk,
       final StorageType storageType,
       final Token<BlockTokenIdentifier> blockToken,
       final String clientName,
@@ -124,7 +124,7 @@ public interface DataTransferProtocol {
    * @param clientName client's name.
    * @param targets target datanodes.
    */
-  public void transferBlock(final ExtendedBlock blk,
+  void transferBlock(final ExtendedBlock blk,
       final Token<BlockTokenIdentifier> blockToken,
       final String clientName,
       final DatanodeInfo[] targets,
@@ -142,7 +142,7 @@ public interface DataTransferProtocol {
    * @param supportsReceiptVerification  True if the client supports
    *                          receipt verification.
    */
-  public void requestShortCircuitFds(final ExtendedBlock blk,
+  void requestShortCircuitFds(final ExtendedBlock blk,
       final Token<BlockTokenIdentifier> blockToken,
       SlotId slotId, int maxVersion, boolean supportsReceiptVerification)
         throws IOException;
@@ -152,14 +152,14 @@ public interface DataTransferProtocol {
    *
    * @param slotId          SlotID used by the earlier file descriptors.
    */
-  public void releaseShortCircuitFds(final SlotId slotId) throws IOException;
+  void releaseShortCircuitFds(final SlotId slotId) throws IOException;
 
   /**
    * Request a short circuit shared memory area from a DataNode.
    *
    * @param clientName       The name of the client.
    */
-  public void requestShortCircuitShm(String clientName) throws IOException;
+  void requestShortCircuitShm(String clientName) throws IOException;
 
   /**
    * Receive a block from a source datanode
@@ -174,7 +174,7 @@ public interface DataTransferProtocol {
    * @param delHint the hint for deleting the block in the original datanode.
    * @param source the source datanode for receiving the block.
    */
-  public void replaceBlock(final ExtendedBlock blk,
+  void replaceBlock(final ExtendedBlock blk,
       final StorageType storageType,
       final Token<BlockTokenIdentifier> blockToken,
       final String delHint,
@@ -187,7 +187,7 @@ public interface DataTransferProtocol {
    * @param blk the block being copied.
    * @param blockToken security token for accessing the block.
    */
-  public void copyBlock(final ExtendedBlock blk,
+  void copyBlock(final ExtendedBlock blk,
       final Token<BlockTokenIdentifier> blockToken) throws IOException;
 
   /**
@@ -197,6 +197,6 @@ public interface DataTransferProtocol {
    * @param blockToken security token for accessing the block.
    * @throws IOException
    */
-  public void blockChecksum(final ExtendedBlock blk,
+  void blockChecksum(final ExtendedBlock blk,
       final Token<BlockTokenIdentifier> blockToken) throws IOException;
 }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/Op.java

@@ -43,7 +43,7 @@ public enum Op {
   /** The code for this operation. */
   public final byte code;
 
-  private Op(byte code) {
+  Op(byte code) {
     this.code = code;
   }
 

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/PacketHeader.java

@@ -51,8 +51,7 @@ import com.google.protobuf.InvalidProtocolBufferException;
 @InterfaceAudience.Private
 @InterfaceStability.Evolving
 public class PacketHeader {
-  private static final int MAX_PROTO_SIZE = 
+  private static final int MAX_PROTO_SIZE = PacketHeaderProto.newBuilder()
-    PacketHeaderProto.newBuilder()
       .setOffsetInBlock(0)
       .setSeqno(0)
       .setLastPacketInBlock(false)
@@ -78,17 +77,17 @@ public class PacketHeader {
         packetLen);
 
     PacketHeaderProto.Builder builder = PacketHeaderProto.newBuilder()
-      .setOffsetInBlock(offsetInBlock)
+        .setOffsetInBlock(offsetInBlock)
-      .setSeqno(seqno)
+        .setSeqno(seqno)
-      .setLastPacketInBlock(lastPacketInBlock)
+        .setLastPacketInBlock(lastPacketInBlock)
-      .setDataLen(dataLen);
+        .setDataLen(dataLen);
 
     if (syncBlock) {
       // Only set syncBlock if it is specified.
       // This is wire-incompatible with Hadoop 2.0.0-alpha due to HDFS-3721
       // because it changes the length of the packet header, and BlockReceiver
       // in that version did not support variable-length headers.
-      builder.setSyncBlock(syncBlock);
+      builder.setSyncBlock(true);
     }
 
     proto = builder.build();
@@ -187,8 +186,8 @@ public class PacketHeader {
 
   /**
    * Perform a sanity check on the packet, returning true if it is sane.
-   * @param lastSeqNo the previous sequence number received - we expect the current
+   * @param lastSeqNo the previous sequence number received - we expect the
-   * sequence number to be larger by 1.
+   *                  current sequence number to be larger by 1.
    */
   public boolean sanityCheck(long lastSeqNo) {
     // We should only have a non-positive data length for the last packet
@@ -196,8 +195,7 @@ public class PacketHeader {
     // The last packet should not contain data
     if (proto.getLastPacketInBlock() && proto.getDataLen() != 0) return false;
     // Seqnos should always increase by 1 with each packet received
-    if (proto.getSeqno() != lastSeqNo + 1) return false;
+    return proto.getSeqno() == lastSeqNo + 1;
-    return true;
   }
 
   @Override

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/ReplaceDatanodeOnFailure.java

@@ -43,7 +43,7 @@ public class ReplaceDatanodeOnFailure {
 
     private final Condition condition;
 
-    private Policy(Condition condition) {
+    Policy(Condition condition) {
       this.condition = condition;
     }
 
@@ -53,9 +53,9 @@ public class ReplaceDatanodeOnFailure {
   }
 
   /** Datanode replacement condition */
-  private static interface Condition {
+  private interface Condition {
     /** Return true unconditionally. */
-    static final Condition TRUE = new Condition() {
+    Condition TRUE = new Condition() {
       @Override
       public boolean satisfy(short replication, DatanodeInfo[] existings,
           int nExistings, boolean isAppend, boolean isHflushed) {
@@ -64,7 +64,7 @@ public class ReplaceDatanodeOnFailure {
     };
 
     /** Return false unconditionally. */
-    static final Condition FALSE = new Condition() {
+    Condition FALSE = new Condition() {
       @Override
       public boolean satisfy(short replication, DatanodeInfo[] existings,
           int nExistings, boolean isAppend, boolean isHflushed) {
@@ -80,26 +80,19 @@ public class ReplaceDatanodeOnFailure {
      *   (1) floor(r/2) >= n; or
      *   (2) r > n and the block is hflushed/appended.
      */
-    static final Condition DEFAULT = new Condition() {
+    Condition DEFAULT = new Condition() {
       @Override
       public boolean satisfy(final short replication,
           final DatanodeInfo[] existings, final int n, final boolean isAppend,
           final boolean isHflushed) {
-        if (replication < 3) {
+        return replication >= 3 &&
-          return false;
+            (n <= (replication / 2) || isAppend || isHflushed);
-        } else {
-          if (n <= (replication/2)) {
-            return true;
-          } else {
-            return isAppend || isHflushed;
-          }
-        }
       }
     };
 
     /** Is the condition satisfied? */
-    public boolean satisfy(short replication, DatanodeInfo[] existings,
+    boolean satisfy(short replication, DatanodeInfo[] existings, int nExistings,
-        int nExistings, boolean isAppend, boolean isHflushed);
+                    boolean isAppend, boolean isHflushed);
   }
 
   private final Policy policy;
@@ -137,14 +130,11 @@ public class ReplaceDatanodeOnFailure {
   public boolean satisfy(
       final short replication, final DatanodeInfo[] existings,
       final boolean isAppend, final boolean isHflushed) {
-    final int n = existings == null? 0: existings.length;
+    final int n = existings == null ? 0 : existings.length;
-    if (n == 0 || n >= replication) {
+    //don't need to add datanode for any policy.
-      //don't need to add datanode for any policy.
+    return !(n == 0 || n >= replication) &&
-      return false;
+        policy.getCondition().satisfy(replication, existings, n, isAppend,
-    } else {
+            isHflushed);
-      return policy.getCondition().satisfy(
-          replication, existings, n, isAppend, isHflushed);
-    }
   }
 
   @Override

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/Sender.java

@@ -65,8 +65,7 @@ public class Sender implements DataTransferProtocol {
   }
 
   /** Initialize a operation. */
-  private static void op(final DataOutput out, final Op op
+  private static void op(final DataOutput out, final Op op) throws IOException {
-      ) throws IOException {
     out.writeShort(DataTransferProtocol.DATA_TRANSFER_VERSION);
     op.write(out);
   }
@@ -80,13 +79,14 @@ public class Sender implements DataTransferProtocol {
     out.flush();
   }
 
-  static private CachingStrategyProto getCachingStrategy(CachingStrategy cachingStrategy) {
+  static private CachingStrategyProto getCachingStrategy(
+      CachingStrategy cachingStrategy) {
     CachingStrategyProto.Builder builder = CachingStrategyProto.newBuilder();
     if (cachingStrategy.getReadahead() != null) {
-      builder.setReadahead(cachingStrategy.getReadahead().longValue());
+      builder.setReadahead(cachingStrategy.getReadahead());
     }
     if (cachingStrategy.getDropBehind() != null) {
-      builder.setDropBehind(cachingStrategy.getDropBehind().booleanValue());
+      builder.setDropBehind(cachingStrategy.getDropBehind());
     }
     return builder.build();
   }
@@ -101,12 +101,13 @@ public class Sender implements DataTransferProtocol {
       final CachingStrategy cachingStrategy) throws IOException {
 
     OpReadBlockProto proto = OpReadBlockProto.newBuilder()
-      .setHeader(DataTransferProtoUtil.buildClientHeader(blk, clientName, blockToken))
+        .setHeader(DataTransferProtoUtil.buildClientHeader(blk, clientName,
-      .setOffset(blockOffset)
+            blockToken))
-      .setLen(length)
+        .setOffset(blockOffset)
-      .setSendChecksums(sendChecksum)
+        .setLen(length)
-      .setCachingStrategy(getCachingStrategy(cachingStrategy))
+        .setSendChecksums(sendChecksum)
-      .build();
+        .setCachingStrategy(getCachingStrategy(cachingStrategy))
+        .build();
 
     send(out, Op.READ_BLOCK, proto);
   }
@@ -134,23 +135,24 @@ public class Sender implements DataTransferProtocol {
         blk, clientName, blockToken);
 
     ChecksumProto checksumProto =
-      DataTransferProtoUtil.toProto(requestedChecksum);
+        DataTransferProtoUtil.toProto(requestedChecksum);
 
     OpWriteBlockProto.Builder proto = OpWriteBlockProto.newBuilder()
-      .setHeader(header)
+        .setHeader(header)
-      .setStorageType(PBHelperClient.convertStorageType(storageType))
+        .setStorageType(PBHelperClient.convertStorageType(storageType))
-      .addAllTargets(PBHelperClient.convert(targets, 1))
+        .addAllTargets(PBHelperClient.convert(targets, 1))
-      .addAllTargetStorageTypes(PBHelperClient.convertStorageTypes(targetStorageTypes, 1))
+        .addAllTargetStorageTypes(
-      .setStage(toProto(stage))
+            PBHelperClient.convertStorageTypes(targetStorageTypes, 1))
-      .setPipelineSize(pipelineSize)
+        .setStage(toProto(stage))
-      .setMinBytesRcvd(minBytesRcvd)
+        .setPipelineSize(pipelineSize)
-      .setMaxBytesRcvd(maxBytesRcvd)
+        .setMinBytesRcvd(minBytesRcvd)
-      .setLatestGenerationStamp(latestGenerationStamp)
+        .setMaxBytesRcvd(maxBytesRcvd)
-      .setRequestedChecksum(checksumProto)
+        .setLatestGenerationStamp(latestGenerationStamp)
-      .setCachingStrategy(getCachingStrategy(cachingStrategy))
+        .setRequestedChecksum(checksumProto)
-      .setAllowLazyPersist(allowLazyPersist)
+        .setCachingStrategy(getCachingStrategy(cachingStrategy))
-      .setPinning(pinning)
+        .setAllowLazyPersist(allowLazyPersist)
-      .addAllTargetPinnings(PBHelperClient.convert(targetPinnings, 1));
+        .setPinning(pinning)
+        .addAllTargetPinnings(PBHelperClient.convert(targetPinnings, 1));
 
     if (source != null) {
       proto.setSource(PBHelperClient.convertDatanodeInfo(source));
@@ -167,11 +169,12 @@ public class Sender implements DataTransferProtocol {
       final StorageType[] targetStorageTypes) throws IOException {
 
     OpTransferBlockProto proto = OpTransferBlockProto.newBuilder()
-      .setHeader(DataTransferProtoUtil.buildClientHeader(
+        .setHeader(DataTransferProtoUtil.buildClientHeader(
-          blk, clientName, blockToken))
+            blk, clientName, blockToken))
-      .addAllTargets(PBHelperClient.convert(targets))
+        .addAllTargets(PBHelperClient.convert(targets))
-      .addAllTargetStorageTypes(PBHelperClient.convertStorageTypes(targetStorageTypes))
+        .addAllTargetStorageTypes(
-      .build();
+            PBHelperClient.convertStorageTypes(targetStorageTypes))
+        .build();
 
     send(out, Op.TRANSFER_BLOCK, proto);
   }
@@ -180,11 +183,11 @@ public class Sender implements DataTransferProtocol {
   public void requestShortCircuitFds(final ExtendedBlock blk,
       final Token<BlockTokenIdentifier> blockToken,
       SlotId slotId, int maxVersion, boolean supportsReceiptVerification)
-        throws IOException {
+      throws IOException {
     OpRequestShortCircuitAccessProto.Builder builder =
         OpRequestShortCircuitAccessProto.newBuilder()
-          .setHeader(DataTransferProtoUtil.buildBaseHeader(
+            .setHeader(DataTransferProtoUtil.buildBaseHeader(
-            blk, blockToken)).setMaxVersion(maxVersion);
+                blk, blockToken)).setMaxVersion(maxVersion);
     if (slotId != null) {
       builder.setSlotId(PBHelperClient.convert(slotId));
     }
@@ -197,7 +200,7 @@ public class Sender implements DataTransferProtocol {
   public void releaseShortCircuitFds(SlotId slotId) throws IOException {
     ReleaseShortCircuitAccessRequestProto.Builder builder =
         ReleaseShortCircuitAccessRequestProto.newBuilder().
-        setSlotId(PBHelperClient.convert(slotId));
+            setSlotId(PBHelperClient.convert(slotId));
     SpanId spanId = Tracer.getCurrentSpanId();
     if (spanId.isValid()) {
       builder.setTraceInfo(DataTransferTraceInfoProto.newBuilder().
@@ -212,7 +215,7 @@ public class Sender implements DataTransferProtocol {
   public void requestShortCircuitShm(String clientName) throws IOException {
     ShortCircuitShmRequestProto.Builder builder =
         ShortCircuitShmRequestProto.newBuilder().
-        setClientName(clientName);
+            setClientName(clientName);
     SpanId spanId = Tracer.getCurrentSpanId();
     if (spanId.isValid()) {
       builder.setTraceInfo(DataTransferTraceInfoProto.newBuilder().
@@ -230,11 +233,11 @@ public class Sender implements DataTransferProtocol {
       final String delHint,
       final DatanodeInfo source) throws IOException {
     OpReplaceBlockProto proto = OpReplaceBlockProto.newBuilder()
-      .setHeader(DataTransferProtoUtil.buildBaseHeader(blk, blockToken))
+        .setHeader(DataTransferProtoUtil.buildBaseHeader(blk, blockToken))
-      .setStorageType(PBHelperClient.convertStorageType(storageType))
+        .setStorageType(PBHelperClient.convertStorageType(storageType))
-      .setDelHint(delHint)
+        .setDelHint(delHint)
-      .setSource(PBHelperClient.convertDatanodeInfo(source))
+        .setSource(PBHelperClient.convertDatanodeInfo(source))
-      .build();
+        .build();
 
     send(out, Op.REPLACE_BLOCK, proto);
   }
@@ -243,8 +246,8 @@ public class Sender implements DataTransferProtocol {
   public void copyBlock(final ExtendedBlock blk,
       final Token<BlockTokenIdentifier> blockToken) throws IOException {
     OpCopyBlockProto proto = OpCopyBlockProto.newBuilder()
-      .setHeader(DataTransferProtoUtil.buildBaseHeader(blk, blockToken))
+        .setHeader(DataTransferProtoUtil.buildBaseHeader(blk, blockToken))
-      .build();
+        .build();
 
     send(out, Op.COPY_BLOCK, proto);
   }
@@ -253,8 +256,8 @@ public class Sender implements DataTransferProtocol {
   public void blockChecksum(final ExtendedBlock blk,
       final Token<BlockTokenIdentifier> blockToken) throws IOException {
     OpBlockChecksumProto proto = OpBlockChecksumProto.newBuilder()
-      .setHeader(DataTransferProtoUtil.buildBaseHeader(blk, blockToken))
+        .setHeader(DataTransferProtoUtil.buildBaseHeader(blk, blockToken))
-      .build();
+        .build();
 
     send(out, Op.BLOCK_CHECKSUM, proto);
   }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/TrustedChannelResolver.java

@@ -39,14 +39,13 @@ public class TrustedChannelResolver implements Configurable {
   /**
    * Returns an instance of TrustedChannelResolver.
    * Looks up the configuration to see if there is custom class specified.
-   * @param conf
    * @return TrustedChannelResolver
    */
   public static TrustedChannelResolver getInstance(Configuration conf) {
     Class<? extends TrustedChannelResolver> clazz =
-      conf.getClass(
+        conf.getClass(
-          HdfsClientConfigKeys.DFS_TRUSTEDCHANNEL_RESOLVER_CLASS,
+            HdfsClientConfigKeys.DFS_TRUSTEDCHANNEL_RESOLVER_CLASS,
-          TrustedChannelResolver.class, TrustedChannelResolver.class);
+            TrustedChannelResolver.class, TrustedChannelResolver.class);
     return ReflectionUtils.newInstance(clazz, conf);
   }
 

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/sasl/DataTransferSaslUtil.java

@@ -6,9 +6,9 @@
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
- *
+ * <p/>
- *     http://www.apache.org/licenses/LICENSE-2.0
+ * http://www.apache.org/licenses/LICENSE-2.0
- *
+ * <p/>
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -69,7 +69,7 @@ import com.google.protobuf.ByteString;
 public final class DataTransferSaslUtil {
 
   private static final Logger LOG = LoggerFactory.getLogger(
-    DataTransferSaslUtil.class);
+      DataTransferSaslUtil.class);
 
   /**
    * Delimiter for the three-part SASL username string.
@@ -97,14 +97,14 @@ public final class DataTransferSaslUtil {
       throw new IOException("Failed to complete SASL handshake");
     }
     Set<String> requestedQop = ImmutableSet.copyOf(Arrays.asList(
-      saslProps.get(Sasl.QOP).split(",")));
+        saslProps.get(Sasl.QOP).split(",")));
     String negotiatedQop = sasl.getNegotiatedQop();
     LOG.debug("Verifying QOP, requested QOP = {}, negotiated QOP = {}",
-      requestedQop, negotiatedQop);
+        requestedQop, negotiatedQop);
     if (!requestedQop.contains(negotiatedQop)) {
       throw new IOException(String.format("SASL handshake completed, but " +
-        "channel does not have acceptable quality of protection, " +
+          "channel does not have acceptable quality of protection, " +
-        "requested = %s, negotiated = %s", requestedQop, negotiatedQop));
+          "requested = %s, negotiated = %s", requestedQop, negotiatedQop));
     }
   }
 
@@ -145,7 +145,7 @@ public final class DataTransferSaslUtil {
    */
   public static char[] encryptionKeyToPassword(byte[] encryptionKey) {
     return new String(Base64.encodeBase64(encryptionKey, false), Charsets.UTF_8)
-      .toCharArray();
+        .toCharArray();
   }
 
   /**
@@ -153,7 +153,6 @@ public final class DataTransferSaslUtil {
    * [host][/ip-address]:port.  The host may be missing.  The IP address (and
    * preceding '/') may be missing.  The port preceded by ':' is always present.
    *
-   * @param peer
    * @return InetAddress from peer
    */
   public static InetAddress getPeerAddress(Peer peer) {
@@ -181,23 +180,26 @@ public final class DataTransferSaslUtil {
     String qops = conf.get(DFS_DATA_TRANSFER_PROTECTION_KEY);
     if (qops == null || qops.isEmpty()) {
       LOG.debug("DataTransferProtocol not using SaslPropertiesResolver, no " +
-        "QOP found in configuration for {}", DFS_DATA_TRANSFER_PROTECTION_KEY);
+          "QOP found in configuration for {}",
+          DFS_DATA_TRANSFER_PROTECTION_KEY);
       return null;
     }
     Configuration saslPropsResolverConf = new Configuration(conf);
     saslPropsResolverConf.set(HADOOP_RPC_PROTECTION, qops);
     Class<? extends SaslPropertiesResolver> resolverClass = conf.getClass(
-      HADOOP_SECURITY_SASL_PROPS_RESOLVER_CLASS,
+        HADOOP_SECURITY_SASL_PROPS_RESOLVER_CLASS,
-      SaslPropertiesResolver.class, SaslPropertiesResolver.class);
+        SaslPropertiesResolver.class, SaslPropertiesResolver.class);
-    resolverClass = conf.getClass(DFS_DATA_TRANSFER_SASL_PROPS_RESOLVER_CLASS_KEY,
+    resolverClass =
-      resolverClass, SaslPropertiesResolver.class);
+        conf.getClass(DFS_DATA_TRANSFER_SASL_PROPS_RESOLVER_CLASS_KEY,
+        resolverClass, SaslPropertiesResolver.class);
     saslPropsResolverConf.setClass(HADOOP_SECURITY_SASL_PROPS_RESOLVER_CLASS,
-      resolverClass, SaslPropertiesResolver.class);
+        resolverClass, SaslPropertiesResolver.class);
     SaslPropertiesResolver resolver = SaslPropertiesResolver.getInstance(
-      saslPropsResolverConf);
+        saslPropsResolverConf);
     LOG.debug("DataTransferProtocol using SaslPropertiesResolver, configured " +
-      "QOP {} = {}, configured class {} = {}", DFS_DATA_TRANSFER_PROTECTION_KEY, qops, 
+            "QOP {} = {}, configured class {} = {}",
-      DFS_DATA_TRANSFER_SASL_PROPS_RESOLVER_CLASS_KEY, resolverClass);
+        DFS_DATA_TRANSFER_PROTECTION_KEY, qops,
+        DFS_DATA_TRANSFER_SASL_PROPS_RESOLVER_CLASS_KEY, resolverClass);
     return resolver;
   }
 
@@ -279,6 +281,7 @@ public final class DataTransferSaslUtil {
           byte[] inIv = new byte[suite.getAlgorithmBlockSize()];
           byte[] outKey = new byte[keyLen];
           byte[] outIv = new byte[suite.getAlgorithmBlockSize()];
+          assert codec != null;
           codec.generateSecureRandom(inKey);
           codec.generateSecureRandom(inIv);
           codec.generateSecureRandom(outKey);
@@ -300,7 +303,7 @@ public final class DataTransferSaslUtil {
    */
   public static void sendSaslMessageAndNegotiatedCipherOption(
       OutputStream out, byte[] payload, CipherOption option)
-          throws IOException {
+      throws IOException {
     DataTransferEncryptorMessageProto.Builder builder =
         DataTransferEncryptorMessageProto.newBuilder();
 
@@ -381,7 +384,7 @@ public final class DataTransferSaslUtil {
    */
   public static void sendSaslMessageAndNegotiationCipherOptions(
       OutputStream out, byte[] payload, List<CipherOption> options)
-          throws IOException {
+      throws IOException {
     DataTransferEncryptorMessageProto.Builder builder =
         DataTransferEncryptorMessageProto.newBuilder();
 
@@ -408,7 +411,7 @@ public final class DataTransferSaslUtil {
    */
   public static SaslResponseWithNegotiatedCipherOption
       readSaslMessageAndNegotiatedCipherOption(InputStream in)
-          throws IOException {
+      throws IOException {
     DataTransferEncryptorMessageProto proto =
         DataTransferEncryptorMessageProto.parseFrom(vintPrefixed(in));
     if (proto.getStatus() == DataTransferEncryptorStatus.ERROR_UNKNOWN_KEY) {
@@ -492,7 +495,7 @@ public final class DataTransferSaslUtil {
    */
   public static void sendSaslMessage(OutputStream out,
       DataTransferEncryptorStatus status, byte[] payload, String message)
-          throws IOException {
+      throws IOException {
     DataTransferEncryptorMessageProto.Builder builder =
         DataTransferEncryptorMessageProto.newBuilder();
 

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/sasl/SaslDataTransferClient.java

@@ -76,7 +76,7 @@ import com.google.common.collect.Lists;
 public class SaslDataTransferClient {
 
   private static final Logger LOG = LoggerFactory.getLogger(
-    SaslDataTransferClient.class);
+      SaslDataTransferClient.class);
 
   private final Configuration conf;
   private final AtomicBoolean fallbackToSimpleAuth;
@@ -138,9 +138,9 @@ public class SaslDataTransferClient {
       throws IOException {
     // The encryption key factory only returns a key if encryption is enabled.
     DataEncryptionKey encryptionKey = !trustedChannelResolver.isTrusted() ?
-      encryptionKeyFactory.newDataEncryptionKey() : null;
+        encryptionKeyFactory.newDataEncryptionKey() : null;
     IOStreamPair ios = send(socket.getInetAddress(), underlyingOut,
-      underlyingIn, encryptionKey, accessToken, datanodeId);
+        underlyingIn, encryptionKey, accessToken, datanodeId);
     return ios != null ? ios : new IOStreamPair(underlyingIn, underlyingOut);
   }
 
@@ -158,8 +158,8 @@ public class SaslDataTransferClient {
       Token<BlockTokenIdentifier> accessToken, DatanodeID datanodeId)
       throws IOException {
     IOStreamPair ios = checkTrustAndSend(getPeerAddress(peer),
-      peer.getOutputStream(), peer.getInputStream(), encryptionKeyFactory,
+        peer.getOutputStream(), peer.getInputStream(), encryptionKeyFactory,
-      accessToken, datanodeId);
+        accessToken, datanodeId);
     // TODO: Consider renaming EncryptedPeer to SaslPeer.
     return ios != null ? new EncryptedPeer(peer, ios) : peer;
   }
@@ -181,7 +181,7 @@ public class SaslDataTransferClient {
       Token<BlockTokenIdentifier> accessToken, DatanodeID datanodeId)
       throws IOException {
     IOStreamPair ios = checkTrustAndSend(socket.getInetAddress(), underlyingOut,
-      underlyingIn, encryptionKeyFactory, accessToken, datanodeId);
+        underlyingIn, encryptionKeyFactory, accessToken, datanodeId);
     return ios != null ? ios : new IOStreamPair(underlyingIn, underlyingOut);
   }
 
@@ -207,13 +207,13 @@ public class SaslDataTransferClient {
         !trustedChannelResolver.isTrusted(addr)) {
       // The encryption key factory only returns a key if encryption is enabled.
       DataEncryptionKey encryptionKey =
-        encryptionKeyFactory.newDataEncryptionKey();
+          encryptionKeyFactory.newDataEncryptionKey();
       return send(addr, underlyingOut, underlyingIn, encryptionKey, accessToken,
-        datanodeId);
+          datanodeId);
     } else {
       LOG.debug(
-        "SASL client skipping handshake on trusted connection for addr = {}, "
+          "SASL client skipping handshake on trusted connection for addr = {}, "
-        + "datanodeId = {}", addr, datanodeId);
+              + "datanodeId = {}", addr, datanodeId);
       return null;
     }
   }
@@ -236,40 +236,38 @@ public class SaslDataTransferClient {
       Token<BlockTokenIdentifier> accessToken, DatanodeID datanodeId)
       throws IOException {
     if (encryptionKey != null) {
-      LOG.debug(
+      LOG.debug("SASL client doing encrypted handshake for addr = {}, "
-        "SASL client doing encrypted handshake for addr = {}, datanodeId = {}",
+          + "datanodeId = {}", addr, datanodeId);
-        addr, datanodeId);
       return getEncryptedStreams(underlyingOut, underlyingIn,
-        encryptionKey);
+          encryptionKey);
     } else if (!UserGroupInformation.isSecurityEnabled()) {
-      LOG.debug(
+      LOG.debug("SASL client skipping handshake in unsecured configuration for "
-        "SASL client skipping handshake in unsecured configuration for "
+          + "addr = {}, datanodeId = {}", addr, datanodeId);
-        + "addr = {}, datanodeId = {}", addr, datanodeId);
       return null;
     } else if (SecurityUtil.isPrivilegedPort(datanodeId.getXferPort())) {
       LOG.debug(
-        "SASL client skipping handshake in secured configuration with "
+          "SASL client skipping handshake in secured configuration with "
-        + "privileged port for addr = {}, datanodeId = {}", addr, datanodeId);
+              + "privileged port for addr = {}, datanodeId = {}",
+          addr, datanodeId);
       return null;
     } else if (fallbackToSimpleAuth != null && fallbackToSimpleAuth.get()) {
       LOG.debug(
-        "SASL client skipping handshake in secured configuration with "
+          "SASL client skipping handshake in secured configuration with "
-        + "unsecured cluster for addr = {}, datanodeId = {}", addr, datanodeId);
+              + "unsecured cluster for addr = {}, datanodeId = {}",
+          addr, datanodeId);
       return null;
     } else if (saslPropsResolver != null) {
       LOG.debug(
-        "SASL client doing general handshake for addr = {}, datanodeId = {}",
+          "SASL client doing general handshake for addr = {}, datanodeId = {}",
-        addr, datanodeId);
+          addr, datanodeId);
-      return getSaslStreams(addr, underlyingOut, underlyingIn, accessToken,
+      return getSaslStreams(addr, underlyingOut, underlyingIn, accessToken);
-        datanodeId);
     } else {
       // It's a secured cluster using non-privileged ports, but no SASL.  The
       // only way this can happen is if the DataNode has
-      // ignore.secure.ports.for.testing configured, so this is a rare edge case.
+      // ignore.secure.ports.for.testing configured so this is a rare edge case.
-      LOG.debug(
+      LOG.debug("SASL client skipping handshake in secured configuration with "
-        "SASL client skipping handshake in secured configuration with no SASL "
+              + "no SASL protection configured for addr = {}, datanodeId = {}",
-        + "protection configured for addr = {}, datanodeId = {}",
+          addr, datanodeId);
-        addr, datanodeId);
       return null;
     }
   }
@@ -287,17 +285,17 @@ public class SaslDataTransferClient {
       InputStream underlyingIn, DataEncryptionKey encryptionKey)
       throws IOException {
     Map<String, String> saslProps = createSaslPropertiesForEncryption(
-      encryptionKey.encryptionAlgorithm);
+        encryptionKey.encryptionAlgorithm);
 
     LOG.debug("Client using encryption algorithm {}",
-      encryptionKey.encryptionAlgorithm);
+        encryptionKey.encryptionAlgorithm);
 
     String userName = getUserNameFromEncryptionKey(encryptionKey);
     char[] password = encryptionKeyToPassword(encryptionKey.encryptionKey);
     CallbackHandler callbackHandler = new SaslClientCallbackHandler(userName,
-      password);
+        password);
     return doSaslHandshake(underlyingOut, underlyingIn, userName, saslProps,
-      callbackHandler);
+        callbackHandler);
   }
 
   /**
@@ -312,7 +310,8 @@ public class SaslDataTransferClient {
       DataEncryptionKey encryptionKey) {
     return encryptionKey.keyId + NAME_DELIMITER +
         encryptionKey.blockPoolId + NAME_DELIMITER +
-        new String(Base64.encodeBase64(encryptionKey.nonce, false), Charsets.UTF_8);
+        new String(Base64.encodeBase64(encryptionKey.nonce, false),
+            Charsets.UTF_8);
   }
 
   /**
@@ -328,7 +327,7 @@ public class SaslDataTransferClient {
      * Creates a new SaslClientCallbackHandler.
      *
      * @param userName SASL user name
-     * @Param password SASL password
+     * @param password SASL password
      */
     public SaslClientCallbackHandler(String userName, char[] password) {
       this.password = password;
@@ -342,15 +341,13 @@ public class SaslDataTransferClient {
       PasswordCallback pc = null;
       RealmCallback rc = null;
       for (Callback callback : callbacks) {
-        if (callback instanceof RealmChoiceCallback) {
+        if (callback instanceof NameCallback) {
-          continue;
-        } else if (callback instanceof NameCallback) {
           nc = (NameCallback) callback;
         } else if (callback instanceof PasswordCallback) {
           pc = (PasswordCallback) callback;
         } else if (callback instanceof RealmCallback) {
           rc = (RealmCallback) callback;
-        } else {
+        } else if (!(callback instanceof RealmChoiceCallback)) {
           throw new UnsupportedCallbackException(callback,
               "Unrecognized SASL client callback");
         }
@@ -374,22 +371,21 @@ public class SaslDataTransferClient {
    * @param underlyingOut connection output stream
    * @param underlyingIn connection input stream
    * @param accessToken connection block access token
-   * @param datanodeId ID of destination DataNode
    * @return new pair of streams, wrapped after SASL negotiation
    * @throws IOException for any error
    */
   private IOStreamPair getSaslStreams(InetAddress addr,
       OutputStream underlyingOut, InputStream underlyingIn,
-      Token<BlockTokenIdentifier> accessToken, DatanodeID datanodeId)
+      Token<BlockTokenIdentifier> accessToken)
       throws IOException {
     Map<String, String> saslProps = saslPropsResolver.getClientProperties(addr);
 
     String userName = buildUserName(accessToken);
     char[] password = buildClientPassword(accessToken);
     CallbackHandler callbackHandler = new SaslClientCallbackHandler(userName,
-      password);
+        password);
     return doSaslHandshake(underlyingOut, underlyingIn, userName, saslProps,
-      callbackHandler);
+        callbackHandler);
   }
 
   /**
@@ -404,7 +400,7 @@ public class SaslDataTransferClient {
    */
   private static String buildUserName(Token<BlockTokenIdentifier> blockToken) {
     return new String(Base64.encodeBase64(blockToken.getIdentifier(), false),
-      Charsets.UTF_8);
+        Charsets.UTF_8);
   }
 
   /**
@@ -416,7 +412,7 @@ public class SaslDataTransferClient {
    */
   private char[] buildClientPassword(Token<BlockTokenIdentifier> blockToken) {
     return new String(Base64.encodeBase64(blockToken.getPassword(), false),
-      Charsets.UTF_8).toCharArray();
+        Charsets.UTF_8).toCharArray();
   }
 
   /**
@@ -438,7 +434,7 @@ public class SaslDataTransferClient {
     DataInputStream in = new DataInputStream(underlyingIn);
 
     SaslParticipant sasl= SaslParticipant.createClientSaslParticipant(userName,
-      saslProps, callbackHandler);
+        saslProps, callbackHandler);
 
     out.writeInt(SASL_TRANSFER_MAGIC_NUMBER);
     out.flush();
@@ -489,7 +485,7 @@ public class SaslDataTransferClient {
       // stream pair.
       return cipherOption != null ? createStreamPair(
           conf, cipherOption, underlyingOut, underlyingIn, false) :
-            sasl.createStreamPair(out, in);
+          sasl.createStreamPair(out, in);
     } catch (IOException ioe) {
       sendGenericSaslErrorMessage(out, ioe.getMessage());
       throw ioe;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientDatanodeProtocolTranslatorPB.java

@@ -115,7 +115,7 @@ public class ClientDatanodeProtocolTranslatorPB implements
       Configuration conf, int socketTimeout, boolean connectToDnViaHostname,
       LocatedBlock locatedBlock) throws IOException {
     rpcProxy = createClientDatanodeProtocolProxy( datanodeid, conf,
-                  socketTimeout, connectToDnViaHostname, locatedBlock);
+        socketTimeout, connectToDnViaHostname, locatedBlock);
   }
 
   public ClientDatanodeProtocolTranslatorPB(InetSocketAddress addr,
@@ -145,7 +145,8 @@ public class ClientDatanodeProtocolTranslatorPB implements
 
   static ClientDatanodeProtocolPB createClientDatanodeProtocolProxy(
       DatanodeID datanodeid, Configuration conf, int socketTimeout,
-      boolean connectToDnViaHostname, LocatedBlock locatedBlock) throws IOException {
+      boolean connectToDnViaHostname, LocatedBlock locatedBlock)
+      throws IOException {
     final String dnAddr = datanodeid.getIpcAddr(connectToDnViaHostname);
     InetSocketAddress addr = NetUtils.createSocketAddr(dnAddr);
     LOG.debug("Connecting to datanode {} addr={}", dnAddr, addr);
@@ -185,8 +186,9 @@ public class ClientDatanodeProtocolTranslatorPB implements
 
   @Override
   public long getReplicaVisibleLength(ExtendedBlock b) throws IOException {
-    GetReplicaVisibleLengthRequestProto req = GetReplicaVisibleLengthRequestProto
+    GetReplicaVisibleLengthRequestProto req =
-        .newBuilder().setBlock(PBHelperClient.convert(b)).build();
+        GetReplicaVisibleLengthRequestProto.newBuilder()
+            .setBlock(PBHelperClient.convert(b)).build();
     try {
       return rpcProxy.getReplicaVisibleLength(NULL_CONTROLLER, req).getLength();
     } catch (ServiceException e) {
@@ -219,8 +221,8 @@ public class ClientDatanodeProtocolTranslatorPB implements
       Token<BlockTokenIdentifier> token) throws IOException {
     GetBlockLocalPathInfoRequestProto req =
         GetBlockLocalPathInfoRequestProto.newBuilder()
-        .setBlock(PBHelperClient.convert(block))
+            .setBlock(PBHelperClient.convert(block))
-        .setToken(PBHelperClient.convert(token)).build();
+            .setToken(PBHelperClient.convert(token)).build();
     GetBlockLocalPathInfoResponseProto resp;
     try {
       resp = rpcProxy.getBlockLocalPathInfo(NULL_CONTROLLER, req);
@@ -294,7 +296,8 @@ public class ClientDatanodeProtocolTranslatorPB implements
   public DatanodeLocalInfo getDatanodeInfo() throws IOException {
     GetDatanodeInfoResponseProto response;
     try {
-      response = rpcProxy.getDatanodeInfo(NULL_CONTROLLER, VOID_GET_DATANODE_INFO);
+      response = rpcProxy.getDatanodeInfo(NULL_CONTROLLER,
+          VOID_GET_DATANODE_INFO);
       return PBHelperClient.convert(response.getLocalInfo());
     } catch (ServiceException e) {
       throw ProtobufHelper.getRemoteException(e);
@@ -311,7 +314,8 @@ public class ClientDatanodeProtocolTranslatorPB implements
   }
 
   @Override
-  public ReconfigurationTaskStatus getReconfigurationStatus() throws IOException {
+  public ReconfigurationTaskStatus getReconfigurationStatus()
+      throws IOException {
     GetReconfigurationStatusResponseProto response;
     Map<PropertyChange, Optional<String>> statusMap = null;
     long startTime;
@@ -361,8 +365,8 @@ public class ClientDatanodeProtocolTranslatorPB implements
     try {
       rpcProxy.triggerBlockReport(NULL_CONTROLLER,
           TriggerBlockReportRequestProto.newBuilder().
-            setIncremental(options.isIncremental()).
+              setIncremental(options.isIncremental()).
-            build());
+              build());
     } catch (ServiceException e) {
       throw ProtobufHelper.getRemoteException(e);
     }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolPB.java

@@ -42,5 +42,5 @@ import org.apache.hadoop.security.token.TokenInfo;
  * add annotations required for security.
  */
 public interface ClientNamenodeProtocolPB extends
-  ClientNamenodeProtocol.BlockingInterface {
+    ClientNamenodeProtocol.BlockingInterface {
 }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolTranslatorPB.java

@@ -18,7 +18,6 @@
 package org.apache.hadoop.hdfs.protocolPB;
 
 import java.io.Closeable;
-import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.EnumSet;
@@ -33,12 +32,9 @@ import org.apache.hadoop.fs.BatchedRemoteIterator.BatchedEntries;
 import org.apache.hadoop.fs.CacheFlag;
 import org.apache.hadoop.fs.ContentSummary;
 import org.apache.hadoop.fs.CreateFlag;
-import org.apache.hadoop.fs.FileAlreadyExistsException;
 import org.apache.hadoop.fs.FsServerDefaults;
 import org.apache.hadoop.fs.Options.Rename;
-import org.apache.hadoop.fs.ParentNotDirectoryException;
 import org.apache.hadoop.fs.StorageType;
-import org.apache.hadoop.fs.UnresolvedLinkException;
 import org.apache.hadoop.fs.XAttr;
 import org.apache.hadoop.fs.XAttrSetFlag;
 import org.apache.hadoop.fs.permission.AclEntry;
@@ -46,7 +42,6 @@ import org.apache.hadoop.fs.permission.AclStatus;
 import org.apache.hadoop.fs.permission.FsAction;
 import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.hdfs.inotify.EventBatchList;
-import org.apache.hadoop.hdfs.protocol.AlreadyBeingCreatedException;
 import org.apache.hadoop.hdfs.protocol.BlockStoragePolicy;
 import org.apache.hadoop.hdfs.protocol.CacheDirectiveEntry;
 import org.apache.hadoop.hdfs.protocol.CacheDirectiveInfo;
@@ -54,7 +49,6 @@ import org.apache.hadoop.hdfs.protocol.CachePoolEntry;
 import org.apache.hadoop.hdfs.protocol.CachePoolInfo;
 import org.apache.hadoop.hdfs.protocol.ClientProtocol;
 import org.apache.hadoop.hdfs.protocol.CorruptFileBlocks;
-import org.apache.hadoop.hdfs.protocol.DSQuotaExceededException;
 import org.apache.hadoop.hdfs.protocol.DatanodeID;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.hdfs.protocol.DirectoryListing;
@@ -67,7 +61,6 @@ import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
 import org.apache.hadoop.hdfs.protocol.LastBlockWithStatus;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
 import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
-import org.apache.hadoop.hdfs.protocol.NSQuotaExceededException;
 import org.apache.hadoop.hdfs.protocol.RollingUpgradeInfo;
 import org.apache.hadoop.hdfs.protocol.SnapshotDiffReport;
 import org.apache.hadoop.hdfs.protocol.SnapshottableDirectoryStatus;
@@ -171,8 +164,6 @@ import org.apache.hadoop.hdfs.protocol.proto.XAttrProtos.RemoveXAttrRequestProto
 import org.apache.hadoop.hdfs.protocol.proto.XAttrProtos.SetXAttrRequestProto;
 import org.apache.hadoop.hdfs.security.token.block.DataEncryptionKey;
 import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier;
-import org.apache.hadoop.hdfs.server.namenode.NotReplicatedYetException;
-import org.apache.hadoop.hdfs.server.namenode.SafeModeException;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeStorageReport;
 import org.apache.hadoop.io.EnumSetWritable;
 import org.apache.hadoop.io.Text;
@@ -181,7 +172,6 @@ import org.apache.hadoop.ipc.ProtocolMetaInterface;
 import org.apache.hadoop.ipc.ProtocolTranslator;
 import org.apache.hadoop.ipc.RPC;
 import org.apache.hadoop.ipc.RpcClientUtil;
-import org.apache.hadoop.security.AccessControlException;
 import org.apache.hadoop.security.proto.SecurityProtos.CancelDelegationTokenRequestProto;
 import org.apache.hadoop.security.proto.SecurityProtos.GetDelegationTokenRequestProto;
 import org.apache.hadoop.security.proto.SecurityProtos.GetDelegationTokenResponseProto;
@@ -207,10 +197,10 @@ public class ClientNamenodeProtocolTranslatorPB implements
   final private ClientNamenodeProtocolPB rpcProxy;
 
   static final GetServerDefaultsRequestProto VOID_GET_SERVER_DEFAULT_REQUEST =
-  GetServerDefaultsRequestProto.newBuilder().build();
+      GetServerDefaultsRequestProto.newBuilder().build();
 
   private final static GetFsStatusRequestProto VOID_GET_FSSTATUS_REQUEST =
-  GetFsStatusRequestProto.newBuilder().build();
+      GetFsStatusRequestProto.newBuilder().build();
 
   private final static SaveNamespaceRequestProto VOID_SAVE_NAMESPACE_REQUEST =
   SaveNamespaceRequestProto.newBuilder().build();
@@ -219,18 +209,18 @@ public class ClientNamenodeProtocolTranslatorPB implements
   RollEditsRequestProto.getDefaultInstance();
 
   private final static RefreshNodesRequestProto VOID_REFRESH_NODES_REQUEST =
-  RefreshNodesRequestProto.newBuilder().build();
+      RefreshNodesRequestProto.newBuilder().build();
 
   private final static FinalizeUpgradeRequestProto
-  VOID_FINALIZE_UPGRADE_REQUEST =
+      VOID_FINALIZE_UPGRADE_REQUEST =
       FinalizeUpgradeRequestProto.newBuilder().build();
 
   private final static GetDataEncryptionKeyRequestProto
-  VOID_GET_DATA_ENCRYPTIONKEY_REQUEST =
+      VOID_GET_DATA_ENCRYPTIONKEY_REQUEST =
       GetDataEncryptionKeyRequestProto.newBuilder().build();
 
   private final static GetStoragePoliciesRequestProto
-  VOID_GET_STORAGE_POLICIES_REQUEST =
+      VOID_GET_STORAGE_POLICIES_REQUEST =
       GetStoragePoliciesRequestProto.newBuilder().build();
 
   public ClientNamenodeProtocolTranslatorPB(ClientNamenodeProtocolPB proxy) {
@@ -244,8 +234,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
   @Override
   public LocatedBlocks getBlockLocations(String src, long offset, long length)
-      throws AccessControlException, FileNotFoundException,
+      throws IOException {
-      UnresolvedLinkException, IOException {
     GetBlockLocationsRequestProto req = GetBlockLocationsRequestProto
         .newBuilder()
         .setSrc(src)
@@ -256,7 +245,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
       GetBlockLocationsResponseProto resp = rpcProxy.getBlockLocations(null,
           req);
       return resp.hasLocations() ?
-        PBHelperClient.convert(resp.getLocations()) : null;
+          PBHelperClient.convert(resp.getLocations()) : null;
     } catch (ServiceException e) {
       throw ProtobufHelper.getRemoteException(e);
     }
@@ -278,11 +267,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
       String clientName, EnumSetWritable<CreateFlag> flag,
       boolean createParent, short replication, long blockSize,
       CryptoProtocolVersion[] supportedVersions)
-      throws AccessControlException, AlreadyBeingCreatedException,
+      throws IOException {
-      DSQuotaExceededException, FileAlreadyExistsException,
-      FileNotFoundException, NSQuotaExceededException,
-      ParentNotDirectoryException, SafeModeException, UnresolvedLinkException,
-      IOException {
     CreateRequestProto.Builder builder = CreateRequestProto.newBuilder()
         .setSrc(src)
         .setMasked(PBHelperClient.convert(masked))
@@ -291,7 +276,8 @@ public class ClientNamenodeProtocolTranslatorPB implements
         .setCreateParent(createParent)
         .setReplication(replication)
         .setBlockSize(blockSize);
-    builder.addAllCryptoProtocolVersion(PBHelperClient.convert(supportedVersions));
+    builder.addAllCryptoProtocolVersion(
+        PBHelperClient.convert(supportedVersions));
     CreateRequestProto req = builder.build();
     try {
       CreateResponseProto res = rpcProxy.create(null, req);
@@ -304,7 +290,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
   @Override
   public boolean truncate(String src, long newLength, String clientName)
-      throws IOException, UnresolvedLinkException {
+      throws IOException {
     TruncateRequestProto req = TruncateRequestProto.newBuilder()
         .setSrc(src)
         .setNewLength(newLength)
@@ -319,18 +305,17 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
   @Override
   public LastBlockWithStatus append(String src, String clientName,
-      EnumSetWritable<CreateFlag> flag) throws AccessControlException,
+      EnumSetWritable<CreateFlag> flag) throws IOException {
-      DSQuotaExceededException, FileNotFoundException, SafeModeException,
-      UnresolvedLinkException, IOException {
     AppendRequestProto req = AppendRequestProto.newBuilder().setSrc(src)
-        .setClientName(clientName).setFlag(PBHelperClient.convertCreateFlag(flag))
+        .setClientName(clientName).setFlag(
+            PBHelperClient.convertCreateFlag(flag))
         .build();
     try {
       AppendResponseProto res = rpcProxy.append(null, req);
       LocatedBlock lastBlock = res.hasBlock() ? PBHelperClient
           .convert(res.getBlock()) : null;
-      HdfsFileStatus stat = (res.hasStat()) ? PBHelperClient.convert(res.getStat())
+      HdfsFileStatus stat = (res.hasStat()) ?
-          : null;
+          PBHelperClient.convert(res.getStat()) : null;
       return new LastBlockWithStatus(lastBlock, stat);
     } catch (ServiceException e) {
       throw ProtobufHelper.getRemoteException(e);
@@ -339,9 +324,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
   @Override
   public boolean setReplication(String src, short replication)
-      throws AccessControlException, DSQuotaExceededException,
+      throws IOException {
-      FileNotFoundException, SafeModeException, UnresolvedLinkException,
-      IOException {
     SetReplicationRequestProto req = SetReplicationRequestProto.newBuilder()
         .setSrc(src)
         .setReplication(replication)
@@ -355,8 +338,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
   @Override
   public void setPermission(String src, FsPermission permission)
-      throws AccessControlException, FileNotFoundException, SafeModeException,
+      throws IOException {
-      UnresolvedLinkException, IOException {
     SetPermissionRequestProto req = SetPermissionRequestProto.newBuilder()
         .setSrc(src)
         .setPermission(PBHelperClient.convert(permission))
@@ -370,14 +352,13 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
   @Override
   public void setOwner(String src, String username, String groupname)
-      throws AccessControlException, FileNotFoundException, SafeModeException,
+      throws IOException {
-      UnresolvedLinkException, IOException {
     SetOwnerRequestProto.Builder req = SetOwnerRequestProto.newBuilder()
         .setSrc(src);
     if (username != null)
-        req.setUsername(username);
+      req.setUsername(username);
     if (groupname != null)
-        req.setGroupname(groupname);
+      req.setGroupname(groupname);
     try {
       rpcProxy.setOwner(null, req.build());
     } catch (ServiceException e) {
@@ -387,11 +368,10 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
   @Override
   public void abandonBlock(ExtendedBlock b, long fileId, String src,
-      String holder) throws AccessControlException, FileNotFoundException,
+      String holder) throws IOException {
-        UnresolvedLinkException, IOException {
     AbandonBlockRequestProto req = AbandonBlockRequestProto.newBuilder()
         .setB(PBHelperClient.convert(b)).setSrc(src).setHolder(holder)
-            .setFileId(fileId).build();
+        .setFileId(fileId).build();
     try {
       rpcProxy.abandonBlock(null, req);
     } catch (ServiceException e) {
@@ -402,10 +382,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
   @Override
   public LocatedBlock addBlock(String src, String clientName,
       ExtendedBlock previous, DatanodeInfo[] excludeNodes, long fileId,
-      String[] favoredNodes)
+      String[] favoredNodes) throws IOException {
-      throws AccessControlException, FileNotFoundException,
-      NotReplicatedYetException, SafeModeException, UnresolvedLinkException,
-      IOException {
     AddBlockRequestProto.Builder req = AddBlockRequestProto.newBuilder()
         .setSrc(src).setClientName(clientName).setFileId(fileId);
     if (previous != null)
@@ -425,10 +402,8 @@ public class ClientNamenodeProtocolTranslatorPB implements
   @Override
   public LocatedBlock getAdditionalDatanode(String src, long fileId,
       ExtendedBlock blk, DatanodeInfo[] existings, String[] existingStorageIDs,
-      DatanodeInfo[] excludes,
+      DatanodeInfo[] excludes, int numAdditionalNodes, String clientName)
-      int numAdditionalNodes, String clientName) throws AccessControlException,
+      throws IOException {
-      FileNotFoundException, SafeModeException, UnresolvedLinkException,
-      IOException {
     GetAdditionalDatanodeRequestProto req = GetAdditionalDatanodeRequestProto
         .newBuilder()
         .setSrc(src)
@@ -450,9 +425,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
   @Override
   public boolean complete(String src, String clientName,
-                          ExtendedBlock last, long fileId)
+      ExtendedBlock last, long fileId) throws IOException {
-      throws AccessControlException, FileNotFoundException, SafeModeException,
-      UnresolvedLinkException, IOException {
     CompleteRequestProto.Builder req = CompleteRequestProto.newBuilder()
         .setSrc(src)
         .setClientName(clientName)
@@ -469,7 +442,8 @@ public class ClientNamenodeProtocolTranslatorPB implements
   @Override
   public void reportBadBlocks(LocatedBlock[] blocks) throws IOException {
     ReportBadBlocksRequestProto req = ReportBadBlocksRequestProto.newBuilder()
-        .addAllBlocks(Arrays.asList(PBHelperClient.convertLocatedBlock(blocks)))
+        .addAllBlocks(Arrays.asList(
+            PBHelperClient.convertLocatedBlock(blocks)))
         .build();
     try {
       rpcProxy.reportBadBlocks(null, req);
@@ -479,8 +453,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
   }
 
   @Override
-  public boolean rename(String src, String dst) throws UnresolvedLinkException,
+  public boolean rename(String src, String dst) throws IOException {
-      IOException {
     RenameRequestProto req = RenameRequestProto.newBuilder()
         .setSrc(src)
         .setDst(dst).build();
@@ -494,10 +467,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
   @Override
   public void rename2(String src, String dst, Rename... options)
-      throws AccessControlException, DSQuotaExceededException,
+      throws IOException {
-      FileAlreadyExistsException, FileNotFoundException,
-      NSQuotaExceededException, ParentNotDirectoryException, SafeModeException,
-      UnresolvedLinkException, IOException {
     boolean overwrite = false;
     if (options != null) {
       for (Rename option : options) {
@@ -519,8 +489,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
   }
 
   @Override
-  public void concat(String trg, String[] srcs) throws IOException,
+  public void concat(String trg, String[] srcs) throws IOException {
-      UnresolvedLinkException {
     ConcatRequestProto req = ConcatRequestProto.newBuilder().
         setTrg(trg).
         addAllSrcs(Arrays.asList(srcs)).build();
@@ -533,10 +502,9 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
 
   @Override
-  public boolean delete(String src, boolean recursive)
+  public boolean delete(String src, boolean recursive) throws IOException {
-      throws AccessControlException, FileNotFoundException, SafeModeException,
+    DeleteRequestProto req = DeleteRequestProto.newBuilder().setSrc(src)
-      UnresolvedLinkException, IOException {
+        .setRecursive(recursive).build();
-    DeleteRequestProto req = DeleteRequestProto.newBuilder().setSrc(src).setRecursive(recursive).build();
     try {
       return rpcProxy.delete(null, req).getResult();
     } catch (ServiceException e) {
@@ -546,10 +514,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
   @Override
   public boolean mkdirs(String src, FsPermission masked, boolean createParent)
-      throws AccessControlException, FileAlreadyExistsException,
+      throws IOException {
-      FileNotFoundException, NSQuotaExceededException,
-      ParentNotDirectoryException, SafeModeException, UnresolvedLinkException,
-      IOException {
     MkdirsRequestProto req = MkdirsRequestProto.newBuilder()
         .setSrc(src)
         .setMasked(PBHelperClient.convert(masked))
@@ -564,8 +529,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
   @Override
   public DirectoryListing getListing(String src, byte[] startAfter,
-      boolean needLocation) throws AccessControlException,
+      boolean needLocation) throws IOException {
-      FileNotFoundException, UnresolvedLinkException, IOException {
     GetListingRequestProto req = GetListingRequestProto.newBuilder()
         .setSrc(src)
         .setStartAfter(ByteString.copyFrom(startAfter))
@@ -583,8 +547,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
   }
 
   @Override
-  public void renewLease(String clientName) throws AccessControlException,
+  public void renewLease(String clientName) throws IOException {
-      IOException {
     RenewLeaseRequestProto req = RenewLeaseRequestProto.newBuilder()
         .setClientName(clientName).build();
     try {
@@ -632,22 +595,22 @@ public class ClientNamenodeProtocolTranslatorPB implements
   }
 
   @Override
-  public DatanodeStorageReport[] getDatanodeStorageReport(DatanodeReportType type)
+  public DatanodeStorageReport[] getDatanodeStorageReport(
-      throws IOException {
+      DatanodeReportType type) throws IOException {
     final GetDatanodeStorageReportRequestProto req
         = GetDatanodeStorageReportRequestProto.newBuilder()
-            .setType(PBHelperClient.convert(type)).build();
+        .setType(PBHelperClient.convert(type)).build();
     try {
       return PBHelperClient.convertDatanodeStorageReports(
-          rpcProxy.getDatanodeStorageReport(null, req).getDatanodeStorageReportsList());
+          rpcProxy.getDatanodeStorageReport(null, req)
+              .getDatanodeStorageReportsList());
     } catch (ServiceException e) {
       throw ProtobufHelper.getRemoteException(e);
     }
   }
 
   @Override
-  public long getPreferredBlockSize(String filename) throws IOException,
+  public long getPreferredBlockSize(String filename) throws IOException {
-      UnresolvedLinkException {
     GetPreferredBlockSizeRequestProto req = GetPreferredBlockSizeRequestProto
         .newBuilder()
         .setFilename(filename)
@@ -660,9 +623,11 @@ public class ClientNamenodeProtocolTranslatorPB implements
   }
 
   @Override
-  public boolean setSafeMode(SafeModeAction action, boolean isChecked) throws IOException {
+  public boolean setSafeMode(SafeModeAction action, boolean isChecked)
+      throws IOException {
     SetSafeModeRequestProto req = SetSafeModeRequestProto.newBuilder()
-        .setAction(PBHelperClient.convert(action)).setChecked(isChecked).build();
+        .setAction(PBHelperClient.convert(action))
+        .setChecked(isChecked).build();
     try {
       return rpcProxy.setSafeMode(null, req).getResult();
     } catch (ServiceException e) {
@@ -671,7 +636,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
   }
 
   @Override
-  public void saveNamespace() throws AccessControlException, IOException {
+  public void saveNamespace() throws IOException {
     try {
       rpcProxy.saveNamespace(null, VOID_SAVE_NAMESPACE_REQUEST);
     } catch (ServiceException e) {
@@ -680,7 +645,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
   }
 
   @Override
-  public long rollEdits() throws AccessControlException, IOException {
+  public long rollEdits() throws IOException {
     try {
       RollEditsResponseProto resp = rpcProxy.rollEdits(null,
           VOID_ROLLEDITS_REQUEST);
@@ -691,8 +656,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
   }
 
   @Override
-  public boolean restoreFailedStorage(String arg) 
+  public boolean restoreFailedStorage(String arg) throws IOException{
-      throws AccessControlException, IOException{
     RestoreFailedStorageRequestProto req = RestoreFailedStorageRequestProto
         .newBuilder()
         .setArg(arg).build();
@@ -722,11 +686,13 @@ public class ClientNamenodeProtocolTranslatorPB implements
   }
 
   @Override
-  public RollingUpgradeInfo rollingUpgrade(RollingUpgradeAction action) throws IOException {
+  public RollingUpgradeInfo rollingUpgrade(RollingUpgradeAction action)
+      throws IOException {
     final RollingUpgradeRequestProto r = RollingUpgradeRequestProto.newBuilder()
         .setAction(PBHelperClient.convert(action)).build();
     try {
-      final RollingUpgradeResponseProto proto = rpcProxy.rollingUpgrade(null, r);
+      final RollingUpgradeResponseProto proto =
+          rpcProxy.rollingUpgrade(null, r);
       if (proto.hasRollingUpgradeInfo()) {
         return PBHelperClient.convert(proto.getRollingUpgradeInfo());
       }
@@ -764,8 +730,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
   }
 
   @Override
-  public HdfsFileStatus getFileInfo(String src) throws AccessControlException,
+  public HdfsFileStatus getFileInfo(String src) throws IOException {
-      FileNotFoundException, UnresolvedLinkException, IOException {
     GetFileInfoRequestProto req = GetFileInfoRequestProto.newBuilder()
         .setSrc(src).build();
     try {
@@ -777,23 +742,21 @@ public class ClientNamenodeProtocolTranslatorPB implements
   }
 
   @Override
-  public HdfsFileStatus getFileLinkInfo(String src)
+  public HdfsFileStatus getFileLinkInfo(String src) throws IOException {
-      throws AccessControlException, UnresolvedLinkException, IOException {
     GetFileLinkInfoRequestProto req = GetFileLinkInfoRequestProto.newBuilder()
         .setSrc(src).build();
     try {
       GetFileLinkInfoResponseProto result = rpcProxy.getFileLinkInfo(null, req);
       return result.hasFs() ?
-          PBHelperClient.convert(rpcProxy.getFileLinkInfo(null, req).getFs()) : null;
+          PBHelperClient.convert(rpcProxy.getFileLinkInfo(null, req).getFs()) :
+          null;
     } catch (ServiceException e) {
       throw ProtobufHelper.getRemoteException(e);
     }
   }
 
   @Override
-  public ContentSummary getContentSummary(String path)
+  public ContentSummary getContentSummary(String path) throws IOException {
-      throws AccessControlException, FileNotFoundException,
-      UnresolvedLinkException, IOException {
     GetContentSummaryRequestProto req = GetContentSummaryRequestProto
         .newBuilder()
         .setPath(path)
@@ -808,9 +771,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
   @Override
   public void setQuota(String path, long namespaceQuota, long storagespaceQuota,
-                       StorageType type)
+      StorageType type) throws IOException {
-      throws AccessControlException, FileNotFoundException,
-      UnresolvedLinkException, IOException {
     final SetQuotaRequestProto.Builder builder
         = SetQuotaRequestProto.newBuilder()
         .setPath(path)
@@ -829,12 +790,10 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
   @Override
   public void fsync(String src, long fileId, String client,
-                    long lastBlockLength)
+      long lastBlockLength) throws IOException {
-      throws AccessControlException, FileNotFoundException,
-      UnresolvedLinkException, IOException {
     FsyncRequestProto req = FsyncRequestProto.newBuilder().setSrc(src)
         .setClient(client).setLastBlockLength(lastBlockLength)
-            .setFileId(fileId).build();
+        .setFileId(fileId).build();
     try {
       rpcProxy.fsync(null, req);
     } catch (ServiceException e) {
@@ -843,9 +802,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
   }
 
   @Override
-  public void setTimes(String src, long mtime, long atime)
+  public void setTimes(String src, long mtime, long atime) throws IOException {
-      throws AccessControlException, FileNotFoundException,
-      UnresolvedLinkException, IOException {
     SetTimesRequestProto req = SetTimesRequestProto.newBuilder()
         .setSrc(src)
         .setMtime(mtime)
@@ -860,10 +817,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
   @Override
   public void createSymlink(String target, String link, FsPermission dirPerm,
-      boolean createParent) throws AccessControlException,
+      boolean createParent) throws IOException {
-      FileAlreadyExistsException, FileNotFoundException,
-      ParentNotDirectoryException, SafeModeException, UnresolvedLinkException,
-      IOException {
     CreateSymlinkRequestProto req = CreateSymlinkRequestProto.newBuilder()
         .setTarget(target)
         .setLink(link)
@@ -878,8 +832,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
   }
 
   @Override
-  public String getLinkTarget(String path) throws AccessControlException,
+  public String getLinkTarget(String path) throws IOException {
-      FileNotFoundException, IOException {
     GetLinkTargetRequestProto req = GetLinkTargetRequestProto.newBuilder()
         .setPath(path).build();
     try {
@@ -908,7 +861,8 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
   @Override
   public void updatePipeline(String clientName, ExtendedBlock oldBlock,
-      ExtendedBlock newBlock, DatanodeID[] newNodes, String[] storageIDs) throws IOException {
+      ExtendedBlock newBlock, DatanodeID[] newNodes, String[] storageIDs)
+      throws IOException {
     UpdatePipelineRequestProto req = UpdatePipelineRequestProto.newBuilder()
         .setClientName(clientName)
         .setOldBlock(PBHelperClient.convert(oldBlock))
@@ -931,9 +885,10 @@ public class ClientNamenodeProtocolTranslatorPB implements
         .setRenewer(renewer == null ? "" : renewer.toString())
         .build();
     try {
-      GetDelegationTokenResponseProto resp = rpcProxy.getDelegationToken(null, req);
+      GetDelegationTokenResponseProto resp =
-      return resp.hasToken() ? PBHelperClient.convertDelegationToken(resp.getToken())
+          rpcProxy.getDelegationToken(null, req);
-          : null;
+      return resp.hasToken() ?
+          PBHelperClient.convertDelegationToken(resp.getToken()) : null;
     } catch (ServiceException e) {
       throw ProtobufHelper.getRemoteException(e);
     }
@@ -942,9 +897,10 @@ public class ClientNamenodeProtocolTranslatorPB implements
   @Override
   public long renewDelegationToken(Token<DelegationTokenIdentifier> token)
       throws IOException {
-    RenewDelegationTokenRequestProto req = RenewDelegationTokenRequestProto.newBuilder().
+    RenewDelegationTokenRequestProto req =
-        setToken(PBHelperClient.convert(token)).
+        RenewDelegationTokenRequestProto.newBuilder().
-        build();
+            setToken(PBHelperClient.convert(token)).
+            build();
     try {
       return rpcProxy.renewDelegationToken(null, req).getNewExpiryTime();
     } catch (ServiceException e) {
@@ -968,9 +924,10 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
   @Override
   public void setBalancerBandwidth(long bandwidth) throws IOException {
-    SetBalancerBandwidthRequestProto req = SetBalancerBandwidthRequestProto.newBuilder()
+    SetBalancerBandwidthRequestProto req =
-        .setBandwidth(bandwidth)
+        SetBalancerBandwidthRequestProto.newBuilder()
-        .build();
+            .setBandwidth(bandwidth)
+            .build();
     try {
       rpcProxy.setBalancerBandwidth(null, req);
     } catch (ServiceException e) {
@@ -990,7 +947,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
     try {
       GetDataEncryptionKeyResponseProto rsp = rpcProxy.getDataEncryptionKey(
           null, VOID_GET_DATA_ENCRYPTIONKEY_REQUEST);
-     return rsp.hasDataEncryptionKey() ? 
+      return rsp.hasDataEncryptionKey() ?
           PBHelperClient.convert(rsp.getDataEncryptionKey()) : null;
     } catch (ServiceException e) {
       throw ProtobufHelper.getRemoteException(e);
@@ -999,8 +956,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
 
   @Override
-  public boolean isFileClosed(String src) throws AccessControlException,
+  public boolean isFileClosed(String src) throws IOException {
-      FileNotFoundException, UnresolvedLinkException, IOException {
     IsFileClosedRequestProto req = IsFileClosedRequestProto.newBuilder()
         .setSrc(src).build();
     try {
@@ -1182,19 +1138,18 @@ public class ClientNamenodeProtocolTranslatorPB implements
   }
 
   @Override
-  public BatchedEntries<CacheDirectiveEntry>
+  public BatchedEntries<CacheDirectiveEntry> listCacheDirectives(long prevId,
-      listCacheDirectives(long prevId,
+      CacheDirectiveInfo filter) throws IOException {
-          CacheDirectiveInfo filter) throws IOException {
     if (filter == null) {
       filter = new CacheDirectiveInfo.Builder().build();
     }
     try {
       return new BatchedCacheEntries(
-        rpcProxy.listCacheDirectives(null,
+          rpcProxy.listCacheDirectives(null,
-          ListCacheDirectivesRequestProto.newBuilder().
+              ListCacheDirectivesRequestProto.newBuilder().
-            setPrevId(prevId).
+                  setPrevId(prevId).
-            setFilter(PBHelperClient.convert(filter)).
+                  setFilter(PBHelperClient.convert(filter)).
-            build()));
+                  build()));
     } catch (ServiceException e) {
       throw ProtobufHelper.getRemoteException(e);
     }
@@ -1229,15 +1184,15 @@ public class ClientNamenodeProtocolTranslatorPB implements
     try {
       rpcProxy.removeCachePool(null,
           RemoveCachePoolRequestProto.newBuilder().
-            setPoolName(cachePoolName).build());
+              setPoolName(cachePoolName).build());
     } catch (ServiceException e) {
       throw ProtobufHelper.getRemoteException(e);
     }
   }
 
   private static class BatchedCachePoolEntries
-    implements BatchedEntries<CachePoolEntry> {
+      implements BatchedEntries<CachePoolEntry> {
-      private final ListCachePoolsResponseProto proto;
+    private final ListCachePoolsResponseProto proto;
 
     public BatchedCachePoolEntries(ListCachePoolsResponseProto proto) {
       this.proto = proto;
@@ -1265,9 +1220,9 @@ public class ClientNamenodeProtocolTranslatorPB implements
       throws IOException {
     try {
       return new BatchedCachePoolEntries(
-        rpcProxy.listCachePools(null,
+          rpcProxy.listCachePools(null,
-          ListCachePoolsRequestProto.newBuilder().
+              ListCachePoolsRequestProto.newBuilder().
-            setPrevPoolName(prevKey).build()));
+                  setPrevPoolName(prevKey).build()));
     } catch (ServiceException e) {
       throw ProtobufHelper.getRemoteException(e);
     }
@@ -1347,9 +1302,9 @@ public class ClientNamenodeProtocolTranslatorPB implements
 
   @Override
   public void createEncryptionZone(String src, String keyName)
-    throws IOException {
+      throws IOException {
     final CreateEncryptionZoneRequestProto.Builder builder =
-      CreateEncryptionZoneRequestProto.newBuilder();
+        CreateEncryptionZoneRequestProto.newBuilder();
     builder.setSrc(src);
     if (keyName != null && !keyName.isEmpty()) {
       builder.setKeyName(keyName);
@@ -1363,8 +1318,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
   }
 
   @Override
-  public EncryptionZone getEZForPath(String src)
+  public EncryptionZone getEZForPath(String src) throws IOException {
-      throws IOException {
     final GetEZForPathRequestProto.Builder builder =
         GetEZForPathRequestProto.newBuilder();
     builder.setSrc(src);
@@ -1386,9 +1340,9 @@ public class ClientNamenodeProtocolTranslatorPB implements
   public BatchedEntries<EncryptionZone> listEncryptionZones(long id)
       throws IOException {
     final ListEncryptionZonesRequestProto req =
-      ListEncryptionZonesRequestProto.newBuilder()
+        ListEncryptionZonesRequestProto.newBuilder()
-          .setId(id)
+            .setId(id)
-          .build();
+            .build();
     try {
       EncryptionZonesProtos.ListEncryptionZonesResponseProto response =
           rpcProxy.listEncryptionZones(null, req);
@@ -1397,8 +1351,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
       for (EncryptionZoneProto p : response.getZonesList()) {
         elements.add(PBHelperClient.convert(p));
       }
-      return new BatchedListEntries<EncryptionZone>(elements,
+      return new BatchedListEntries<>(elements, response.getHasMore());
-          response.getHasMore());
     } catch (ServiceException e) {
       throw ProtobufHelper.getRemoteException(e);
     }
@@ -1436,9 +1389,9 @@ public class ClientNamenodeProtocolTranslatorPB implements
   }
 
   @Override
-  public List<XAttr> listXAttrs(String src)
+  public List<XAttr> listXAttrs(String src) throws IOException {
-      throws IOException {
+    ListXAttrsRequestProto.Builder builder =
-    ListXAttrsRequestProto.Builder builder = ListXAttrsRequestProto.newBuilder();
+        ListXAttrsRequestProto.newBuilder();
     builder.setSrc(src);
     ListXAttrsRequestProto req = builder.build();
     try {

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelperClient.java

@@ -207,34 +207,34 @@ public class PBHelperClient {
   public static ExtendedBlockProto convert(final ExtendedBlock b) {
     if (b == null) return null;
     return ExtendedBlockProto.newBuilder().
-      setPoolId(b.getBlockPoolId()).
+        setPoolId(b.getBlockPoolId()).
-      setBlockId(b.getBlockId()).
+        setBlockId(b.getBlockId()).
-      setNumBytes(b.getNumBytes()).
+        setNumBytes(b.getNumBytes()).
-      setGenerationStamp(b.getGenerationStamp()).
+        setGenerationStamp(b.getGenerationStamp()).
-      build();
+        build();
   }
 
   public static TokenProto convert(Token<?> tok) {
     return TokenProto.newBuilder().
-      setIdentifier(ByteString.copyFrom(tok.getIdentifier())).
+        setIdentifier(ByteString.copyFrom(tok.getIdentifier())).
-      setPassword(ByteString.copyFrom(tok.getPassword())).
+        setPassword(ByteString.copyFrom(tok.getPassword())).
-      setKind(tok.getKind().toString()).
+        setKind(tok.getKind().toString()).
-      setService(tok.getService().toString()).build();
+        setService(tok.getService().toString()).build();
   }
 
   public static ShortCircuitShmIdProto convert(ShmId shmId) {
     return ShortCircuitShmIdProto.newBuilder().
-      setHi(shmId.getHi()).
+        setHi(shmId.getHi()).
-      setLo(shmId.getLo()).
+        setLo(shmId.getLo()).
-      build();
+        build();
 
   }
 
   public static ShortCircuitShmSlotProto convert(SlotId slotId) {
     return ShortCircuitShmSlotProto.newBuilder().
-      setShmId(convert(slotId.getShmId())).
+        setShmId(convert(slotId.getShmId())).
-      setSlotIdx(slotId.getSlotIdx()).
+        setSlotIdx(slotId.getSlotIdx()).
-      build();
+        build();
   }
 
   public static DatanodeIDProto convert(DatanodeID dn) {
@@ -242,23 +242,24 @@ public class PBHelperClient {
     // which is the same as the DatanodeUuid. Since StorageID is a required
     // field we pass the empty string if the DatanodeUuid is not yet known.
     return DatanodeIDProto.newBuilder()
-      .setIpAddr(dn.getIpAddr())
+        .setIpAddr(dn.getIpAddr())
-      .setHostName(dn.getHostName())
+        .setHostName(dn.getHostName())
-      .setXferPort(dn.getXferPort())
+        .setXferPort(dn.getXferPort())
-      .setDatanodeUuid(dn.getDatanodeUuid() != null ? dn.getDatanodeUuid() : "")
+        .setDatanodeUuid(dn.getDatanodeUuid() != null ?
-      .setInfoPort(dn.getInfoPort())
+            dn.getDatanodeUuid() : "")
-      .setInfoSecurePort(dn.getInfoSecurePort())
+        .setInfoPort(dn.getInfoPort())
-      .setIpcPort(dn.getIpcPort()).build();
+        .setInfoSecurePort(dn.getInfoSecurePort())
+        .setIpcPort(dn.getIpcPort()).build();
   }
 
   public static DatanodeInfoProto.AdminState convert(
-    final DatanodeInfo.AdminStates inAs) {
+      final DatanodeInfo.AdminStates inAs) {
     switch (inAs) {
-      case NORMAL: return  DatanodeInfoProto.AdminState.NORMAL;
+    case NORMAL: return  DatanodeInfoProto.AdminState.NORMAL;
-      case DECOMMISSION_INPROGRESS:
+    case DECOMMISSION_INPROGRESS:
-        return DatanodeInfoProto.AdminState.DECOMMISSION_INPROGRESS;
+      return DatanodeInfoProto.AdminState.DECOMMISSION_INPROGRESS;
-      case DECOMMISSIONED: return DatanodeInfoProto.AdminState.DECOMMISSIONED;
+    case DECOMMISSIONED: return DatanodeInfoProto.AdminState.DECOMMISSIONED;
-      default: return DatanodeInfoProto.AdminState.NORMAL;
+    default: return DatanodeInfoProto.AdminState.NORMAL;
     }
   }
 
@@ -271,23 +272,23 @@ public class PBHelperClient {
       builder.setUpgradeDomain(info.getUpgradeDomain());
     }
     builder
-      .setId(convert((DatanodeID) info))
+        .setId(convert((DatanodeID) info))
-      .setCapacity(info.getCapacity())
+        .setCapacity(info.getCapacity())
-      .setDfsUsed(info.getDfsUsed())
+        .setDfsUsed(info.getDfsUsed())
-      .setRemaining(info.getRemaining())
+        .setRemaining(info.getRemaining())
-      .setBlockPoolUsed(info.getBlockPoolUsed())
+        .setBlockPoolUsed(info.getBlockPoolUsed())
-      .setCacheCapacity(info.getCacheCapacity())
+        .setCacheCapacity(info.getCacheCapacity())
-      .setCacheUsed(info.getCacheUsed())
+        .setCacheUsed(info.getCacheUsed())
-      .setLastUpdate(info.getLastUpdate())
+        .setLastUpdate(info.getLastUpdate())
-      .setLastUpdateMonotonic(info.getLastUpdateMonotonic())
+        .setLastUpdateMonotonic(info.getLastUpdateMonotonic())
-      .setXceiverCount(info.getXceiverCount())
+        .setXceiverCount(info.getXceiverCount())
-      .setAdminState(convert(info.getAdminState()))
+        .setAdminState(convert(info.getAdminState()))
-      .build();
+        .build();
     return builder.build();
   }
 
   public static List<? extends HdfsProtos.DatanodeInfoProto> convert(
-    DatanodeInfo[] dnInfos) {
+      DatanodeInfo[] dnInfos) {
     return convert(dnInfos, 0);
   }
 
@@ -296,11 +297,11 @@ public class PBHelperClient {
    * {@code startIdx}.
    */
   public static List<? extends HdfsProtos.DatanodeInfoProto> convert(
-    DatanodeInfo[] dnInfos, int startIdx) {
+      DatanodeInfo[] dnInfos, int startIdx) {
     if (dnInfos == null)
       return null;
     ArrayList<HdfsProtos.DatanodeInfoProto> protos = Lists
-      .newArrayListWithCapacity(dnInfos.length);
+        .newArrayListWithCapacity(dnInfos.length);
     for (int i = startIdx; i < dnInfos.length; i++) {
       protos.add(convert(dnInfos[i]));
     }
@@ -337,48 +338,48 @@ public class PBHelperClient {
 
   public static StorageTypeProto convertStorageType(StorageType type) {
     switch(type) {
-      case DISK:
+    case DISK:
-        return StorageTypeProto.DISK;
+      return StorageTypeProto.DISK;
-      case SSD:
+    case SSD:
-        return StorageTypeProto.SSD;
+      return StorageTypeProto.SSD;
-      case ARCHIVE:
+    case ARCHIVE:
-        return StorageTypeProto.ARCHIVE;
+      return StorageTypeProto.ARCHIVE;
-      case RAM_DISK:
+    case RAM_DISK:
-        return StorageTypeProto.RAM_DISK;
+      return StorageTypeProto.RAM_DISK;
-      default:
+    default:
-        throw new IllegalStateException(
+      throw new IllegalStateException(
           "BUG: StorageType not found, type=" + type);
     }
   }
 
   public static StorageType convertStorageType(StorageTypeProto type) {
     switch(type) {
-      case DISK:
+    case DISK:
-        return StorageType.DISK;
+      return StorageType.DISK;
-      case SSD:
+    case SSD:
-        return StorageType.SSD;
+      return StorageType.SSD;
-      case ARCHIVE:
+    case ARCHIVE:
-        return StorageType.ARCHIVE;
+      return StorageType.ARCHIVE;
-      case RAM_DISK:
+    case RAM_DISK:
-        return StorageType.RAM_DISK;
+      return StorageType.RAM_DISK;
-      default:
+    default:
-        throw new IllegalStateException(
+      throw new IllegalStateException(
           "BUG: StorageTypeProto not found, type=" + type);
     }
   }
 
   public static List<StorageTypeProto> convertStorageTypes(
-    StorageType[] types) {
+      StorageType[] types) {
     return convertStorageTypes(types, 0);
   }
 
   public static List<StorageTypeProto> convertStorageTypes(
-    StorageType[] types, int startIdx) {
+      StorageType[] types, int startIdx) {
     if (types == null) {
       return null;
     }
     final List<StorageTypeProto> protos = new ArrayList<>(
-      types.length);
+        types.length);
     for (int i = startIdx; i < types.length; ++i) {
       protos.add(convertStorageType(types[i]));
     }
@@ -386,7 +387,7 @@ public class PBHelperClient {
   }
 
   public static InputStream vintPrefixed(final InputStream input)
-    throws IOException {
+      throws IOException {
     final int firstByte = input.read();
     if (firstByte == -1) {
       throw new EOFException("Premature EOF: no length prefix available");
@@ -438,8 +439,8 @@ public class PBHelperClient {
 
   public static HdfsProtos.CipherOptionProto convert(CipherOption option) {
     if (option != null) {
-      HdfsProtos.CipherOptionProto.Builder builder = HdfsProtos.CipherOptionProto.
+      HdfsProtos.CipherOptionProto.Builder builder =
-          newBuilder();
+          HdfsProtos.CipherOptionProto.newBuilder();
       if (option.getCipherSuite() != null) {
         builder.setSuite(convert(option.getCipherSuite()));
       }
@@ -514,7 +515,8 @@ public class PBHelperClient {
       storageIDs = null;
     } else {
       Preconditions.checkState(storageIDsCount == locs.size());
-      storageIDs = proto.getStorageIDsList().toArray(new String[storageIDsCount]);
+      storageIDs = proto.getStorageIDsList()
+          .toArray(new String[storageIDsCount]);
     }
 
     // Set values from the isCached list, re-using references from loc
@@ -550,7 +552,7 @@ public class PBHelperClient {
       List<StorageTypeProto> storageTypesList, int expectedSize) {
     final StorageType[] storageTypes = new StorageType[expectedSize];
     if (storageTypesList.size() != expectedSize) {
-     // missing storage types
+      // missing storage types
       Preconditions.checkState(storageTypesList.isEmpty());
       Arrays.fill(storageTypes, StorageType.DEFAULT);
     } else {
@@ -570,9 +572,9 @@ public class PBHelperClient {
 
   // DatanodeId
   public static DatanodeID convert(DatanodeIDProto dn) {
-    return new DatanodeID(dn.getIpAddr(), dn.getHostName(), dn.getDatanodeUuid(),
+    return new DatanodeID(dn.getIpAddr(), dn.getHostName(),
-        dn.getXferPort(), dn.getInfoPort(), dn.hasInfoSecurePort() ? dn
+        dn.getDatanodeUuid(), dn.getXferPort(), dn.getInfoPort(),
-        .getInfoSecurePort() : 0, dn.getIpcPort());
+        dn.hasInfoSecurePort() ? dn.getInfoSecurePort() : 0, dn.getIpcPort());
   }
 
   public static AdminStates convert(AdminState adminState) {
@@ -611,8 +613,8 @@ public class PBHelperClient {
     return policies;
   }
 
-  public static EventBatchList convert(GetEditsFromTxidResponseProto resp) throws
+  public static EventBatchList convert(GetEditsFromTxidResponseProto resp)
-    IOException {
+      throws IOException {
     final InotifyProtos.EventsListProto list = resp.getEventsList();
     final long firstTxid = list.getFirstTxid();
     final long lastTxid = list.getLastTxid();
@@ -631,82 +633,82 @@ public class PBHelperClient {
       List<Event> events = Lists.newArrayList();
       for (InotifyProtos.EventProto p : bp.getEventsList()) {
         switch (p.getType()) {
-          case EVENT_CLOSE:
+        case EVENT_CLOSE:
-            InotifyProtos.CloseEventProto close =
+          InotifyProtos.CloseEventProto close =
-                InotifyProtos.CloseEventProto.parseFrom(p.getContents());
+              InotifyProtos.CloseEventProto.parseFrom(p.getContents());
-            events.add(new Event.CloseEvent(close.getPath(),
+          events.add(new Event.CloseEvent(close.getPath(),
-                close.getFileSize(), close.getTimestamp()));
+              close.getFileSize(), close.getTimestamp()));
-            break;
+          break;
-          case EVENT_CREATE:
+        case EVENT_CREATE:
-            InotifyProtos.CreateEventProto create =
+          InotifyProtos.CreateEventProto create =
-                InotifyProtos.CreateEventProto.parseFrom(p.getContents());
+              InotifyProtos.CreateEventProto.parseFrom(p.getContents());
-            events.add(new Event.CreateEvent.Builder()
+          events.add(new Event.CreateEvent.Builder()
-                .iNodeType(createTypeConvert(create.getType()))
+              .iNodeType(createTypeConvert(create.getType()))
-                .path(create.getPath())
+              .path(create.getPath())
-                .ctime(create.getCtime())
+              .ctime(create.getCtime())
-                .ownerName(create.getOwnerName())
+              .ownerName(create.getOwnerName())
-                .groupName(create.getGroupName())
+              .groupName(create.getGroupName())
-                .perms(convert(create.getPerms()))
+              .perms(convert(create.getPerms()))
-                .replication(create.getReplication())
+              .replication(create.getReplication())
-                .symlinkTarget(create.getSymlinkTarget().isEmpty() ? null :
+              .symlinkTarget(create.getSymlinkTarget().isEmpty() ? null :
-                    create.getSymlinkTarget())
+                  create.getSymlinkTarget())
-                .defaultBlockSize(create.getDefaultBlockSize())
+              .defaultBlockSize(create.getDefaultBlockSize())
-                .overwrite(create.getOverwrite()).build());
+              .overwrite(create.getOverwrite()).build());
-            break;
+          break;
-          case EVENT_METADATA:
+        case EVENT_METADATA:
-            InotifyProtos.MetadataUpdateEventProto meta =
+          InotifyProtos.MetadataUpdateEventProto meta =
-                InotifyProtos.MetadataUpdateEventProto.parseFrom(p.getContents());
+              InotifyProtos.MetadataUpdateEventProto.parseFrom(p.getContents());
-            events.add(new Event.MetadataUpdateEvent.Builder()
+          events.add(new Event.MetadataUpdateEvent.Builder()
-                .path(meta.getPath())
+              .path(meta.getPath())
-                .metadataType(metadataUpdateTypeConvert(meta.getType()))
+              .metadataType(metadataUpdateTypeConvert(meta.getType()))
-                .mtime(meta.getMtime())
+              .mtime(meta.getMtime())
-                .atime(meta.getAtime())
+              .atime(meta.getAtime())
-                .replication(meta.getReplication())
+              .replication(meta.getReplication())
-                .ownerName(
+              .ownerName(
-                    meta.getOwnerName().isEmpty() ? null : meta.getOwnerName())
+                  meta.getOwnerName().isEmpty() ? null : meta.getOwnerName())
-                .groupName(
+              .groupName(
-                    meta.getGroupName().isEmpty() ? null : meta.getGroupName())
+                  meta.getGroupName().isEmpty() ? null : meta.getGroupName())
-                .perms(meta.hasPerms() ? convert(meta.getPerms()) : null)
+              .perms(meta.hasPerms() ? convert(meta.getPerms()) : null)
-                .acls(meta.getAclsList().isEmpty() ? null : convertAclEntry(
+              .acls(meta.getAclsList().isEmpty() ? null : convertAclEntry(
-                    meta.getAclsList()))
+                  meta.getAclsList()))
-                .xAttrs(meta.getXAttrsList().isEmpty() ? null : convertXAttrs(
+              .xAttrs(meta.getXAttrsList().isEmpty() ? null : convertXAttrs(
-                    meta.getXAttrsList()))
+                  meta.getXAttrsList()))
-                .xAttrsRemoved(meta.getXAttrsRemoved())
+              .xAttrsRemoved(meta.getXAttrsRemoved())
-                .build());
+              .build());
-            break;
+          break;
-          case EVENT_RENAME:
+        case EVENT_RENAME:
-            InotifyProtos.RenameEventProto rename =
+          InotifyProtos.RenameEventProto rename =
-                InotifyProtos.RenameEventProto.parseFrom(p.getContents());
+              InotifyProtos.RenameEventProto.parseFrom(p.getContents());
-            events.add(new Event.RenameEvent.Builder()
+          events.add(new Event.RenameEvent.Builder()
-                  .srcPath(rename.getSrcPath())
+              .srcPath(rename.getSrcPath())
-                  .dstPath(rename.getDestPath())
+              .dstPath(rename.getDestPath())
-                  .timestamp(rename.getTimestamp())
+              .timestamp(rename.getTimestamp())
-                  .build());
+              .build());
-            break;
+          break;
-          case EVENT_APPEND:
+        case EVENT_APPEND:
-            InotifyProtos.AppendEventProto append =
+          InotifyProtos.AppendEventProto append =
-                InotifyProtos.AppendEventProto.parseFrom(p.getContents());
+              InotifyProtos.AppendEventProto.parseFrom(p.getContents());
-            events.add(new Event.AppendEvent.Builder().path(append.getPath())
+          events.add(new Event.AppendEvent.Builder().path(append.getPath())
-                .newBlock(append.hasNewBlock() && append.getNewBlock())
+              .newBlock(append.hasNewBlock() && append.getNewBlock())
-                .build());
+              .build());
-            break;
+          break;
-          case EVENT_UNLINK:
+        case EVENT_UNLINK:
-            InotifyProtos.UnlinkEventProto unlink =
+          InotifyProtos.UnlinkEventProto unlink =
-                InotifyProtos.UnlinkEventProto.parseFrom(p.getContents());
+              InotifyProtos.UnlinkEventProto.parseFrom(p.getContents());
-            events.add(new Event.UnlinkEvent.Builder()
+          events.add(new Event.UnlinkEvent.Builder()
-                  .path(unlink.getPath())
+              .path(unlink.getPath())
-                  .timestamp(unlink.getTimestamp())
+              .timestamp(unlink.getTimestamp())
-                  .build());
+              .build());
-            break;
+          break;
-          case EVENT_TRUNCATE:
+        case EVENT_TRUNCATE:
-            InotifyProtos.TruncateEventProto truncate =
+          InotifyProtos.TruncateEventProto truncate =
-                InotifyProtos.TruncateEventProto.parseFrom(p.getContents());
+              InotifyProtos.TruncateEventProto.parseFrom(p.getContents());
-            events.add(new Event.TruncateEvent(truncate.getPath(),
+          events.add(new Event.TruncateEvent(truncate.getPath(),
-                truncate.getFileSize(), truncate.getTimestamp()));
+              truncate.getFileSize(), truncate.getTimestamp()));
-            break;
+          break;
-          default:
+        default:
-            throw new RuntimeException("Unexpected inotify event type: " +
+          throw new RuntimeException("Unexpected inotify event type: " +
-                p.getType());
+              p.getType());
         }
       }
       batches.add(new EventBatch(txid, events.toArray(new Event[0])));
@@ -878,7 +880,7 @@ public class PBHelperClient {
   }
 
   static InotifyProtos.INodeType createTypeConvert(Event.CreateEvent.INodeType
-                                                       type) {
+      type) {
     switch (type) {
     case DIRECTORY:
       return InotifyProtos.INodeType.I_TYPE_DIRECTORY;
@@ -1090,7 +1092,7 @@ public class PBHelperClient {
     String poolName = checkNotNull(proto.getPoolName());
     CachePoolInfo info = new CachePoolInfo(poolName);
     if (proto.hasOwnerName()) {
-        info.setOwnerName(proto.getOwnerName());
+      info.setOwnerName(proto.getOwnerName());
     }
     if (proto.hasGroupName()) {
       info.setGroupName(proto.getGroupName());
@@ -1138,8 +1140,7 @@ public class PBHelperClient {
     return builder.build();
   }
 
-  public static CacheDirectiveInfoProto convert
+  public static CacheDirectiveInfoProto convert(CacheDirectiveInfo info) {
-      (CacheDirectiveInfo info) {
     CacheDirectiveInfoProto.Builder builder =
         CacheDirectiveInfoProto.newBuilder();
     if (info.getId() != null) {
@@ -1184,10 +1185,8 @@ public class PBHelperClient {
     return builder.build();
   }
 
-  public static CacheDirectiveInfo convert
+  public static CacheDirectiveInfo convert(CacheDirectiveInfoProto proto) {
-      (CacheDirectiveInfoProto proto) {
+    CacheDirectiveInfo.Builder builder = new CacheDirectiveInfo.Builder();
-    CacheDirectiveInfo.Builder builder =
-        new CacheDirectiveInfo.Builder();
     if (proto.hasId()) {
       builder.setId(proto.getId());
     }
@@ -1223,7 +1222,8 @@ public class PBHelperClient {
     return value;
   }
 
-  public static SnapshotDiffReport convert(SnapshotDiffReportProto reportProto) {
+  public static SnapshotDiffReport convert(
+      SnapshotDiffReportProto reportProto) {
     if (reportProto == null) {
       return null;
     }
@@ -1442,8 +1442,7 @@ public class PBHelperClient {
     }
   }
 
-  public static SafeModeActionProto convert(
+  public static SafeModeActionProto convert(SafeModeAction a) {
-      SafeModeAction a) {
     switch (a) {
     case SAFEMODE_LEAVE:
       return SafeModeActionProto.SAFEMODE_LEAVE;
@@ -1469,16 +1468,18 @@ public class PBHelperClient {
     result[ClientProtocol.GET_STATS_CAPACITY_IDX] = res.getCapacity();
     result[ClientProtocol.GET_STATS_USED_IDX] = res.getUsed();
     result[ClientProtocol.GET_STATS_REMAINING_IDX] = res.getRemaining();
-    result[ClientProtocol.GET_STATS_UNDER_REPLICATED_IDX] = res.getUnderReplicated();
+    result[ClientProtocol.GET_STATS_UNDER_REPLICATED_IDX] =
-    result[ClientProtocol.GET_STATS_CORRUPT_BLOCKS_IDX] = res.getCorruptBlocks();
+        res.getUnderReplicated();
-    result[ClientProtocol.GET_STATS_MISSING_BLOCKS_IDX] = res.getMissingBlocks();
+    result[ClientProtocol.GET_STATS_CORRUPT_BLOCKS_IDX] =
+        res.getCorruptBlocks();
+    result[ClientProtocol.GET_STATS_MISSING_BLOCKS_IDX] =
+        res.getMissingBlocks();
     result[ClientProtocol.GET_STATS_MISSING_REPL_ONE_BLOCKS_IDX] =
         res.getMissingReplOneBlocks();
     return result;
   }
 
-  public static DatanodeReportTypeProto
+  public static DatanodeReportTypeProto convert(DatanodeReportType t) {
-    convert(DatanodeReportType t) {
     switch (t) {
     case ALL: return DatanodeReportTypeProto.ALL;
     case LIVE: return DatanodeReportTypeProto.LIVE;
@@ -1636,8 +1637,8 @@ public class PBHelperClient {
       DatanodeStorageReport[] reports) {
     final List<DatanodeStorageReportProto> protos
         = new ArrayList<>(reports.length);
-    for(int i = 0; i < reports.length; i++) {
+    for (DatanodeStorageReport report : reports) {
-      protos.add(convertDatanodeStorageReport(reports[i]));
+      protos.add(convertDatanodeStorageReport(report));
     }
     return protos;
   }
@@ -1682,20 +1683,20 @@ public class PBHelperClient {
   public static FsServerDefaultsProto convert(FsServerDefaults fs) {
     if (fs == null) return null;
     return FsServerDefaultsProto.newBuilder().
-      setBlockSize(fs.getBlockSize()).
+        setBlockSize(fs.getBlockSize()).
-      setBytesPerChecksum(fs.getBytesPerChecksum()).
+        setBytesPerChecksum(fs.getBytesPerChecksum()).
-      setWritePacketSize(fs.getWritePacketSize())
+        setWritePacketSize(fs.getWritePacketSize())
-      .setReplication(fs.getReplication())
+        .setReplication(fs.getReplication())
-      .setFileBufferSize(fs.getFileBufferSize())
+        .setFileBufferSize(fs.getFileBufferSize())
-      .setEncryptDataTransfer(fs.getEncryptDataTransfer())
+        .setEncryptDataTransfer(fs.getEncryptDataTransfer())
-      .setTrashInterval(fs.getTrashInterval())
+        .setTrashInterval(fs.getTrashInterval())
-      .setChecksumType(convert(fs.getChecksumType()))
+        .setChecksumType(convert(fs.getChecksumType()))
-      .build();
+        .build();
   }
 
   public static EnumSetWritable<CreateFlag> convertCreateFlag(int flag) {
     EnumSet<CreateFlag> result =
-       EnumSet.noneOf(CreateFlag.class);
+        EnumSet.noneOf(CreateFlag.class);
     if ((flag & CreateFlagProto.APPEND_VALUE) == CreateFlagProto.APPEND_VALUE) {
       result.add(CreateFlag.APPEND);
     }
@@ -1714,7 +1715,7 @@ public class PBHelperClient {
         == CreateFlagProto.NEW_BLOCK_VALUE) {
       result.add(CreateFlag.NEW_BLOCK);
     }
-    return new EnumSetWritable<CreateFlag>(result, CreateFlag.class);
+    return new EnumSetWritable<>(result, CreateFlag.class);
   }
 
   public static EnumSet<CacheFlag> convertCacheFlags(int flags) {
@@ -1736,20 +1737,20 @@ public class PBHelperClient {
     }
 
     HdfsFileStatusProto.Builder builder =
-     HdfsFileStatusProto.newBuilder().
+        HdfsFileStatusProto.newBuilder().
-      setLength(fs.getLen()).
+            setLength(fs.getLen()).
-      setFileType(fType).
+            setFileType(fType).
-      setBlockReplication(fs.getReplication()).
+            setBlockReplication(fs.getReplication()).
-      setBlocksize(fs.getBlockSize()).
+            setBlocksize(fs.getBlockSize()).
-      setModificationTime(fs.getModificationTime()).
+            setModificationTime(fs.getModificationTime()).
-      setAccessTime(fs.getAccessTime()).
+            setAccessTime(fs.getAccessTime()).
-      setPermission(convert(fs.getPermission())).
+            setPermission(convert(fs.getPermission())).
-      setOwner(fs.getOwner()).
+            setOwner(fs.getOwner()).
-      setGroup(fs.getGroup()).
+            setGroup(fs.getGroup()).
-      setFileId(fs.getFileId()).
+            setFileId(fs.getFileId()).
-      setChildrenNum(fs.getChildrenNum()).
+            setChildrenNum(fs.getChildrenNum()).
-      setPath(ByteString.copyFrom(fs.getLocalNameInBytes())).
+            setPath(ByteString.copyFrom(fs.getLocalNameInBytes())).
-      setStoragePolicy(fs.getStoragePolicy());
+            setStoragePolicy(fs.getStoragePolicy());
     if (fs.isSymlink())  {
       builder.setSymlink(ByteString.copyFrom(fs.getSymlinkInBytes()));
     }
@@ -1779,9 +1780,11 @@ public class PBHelperClient {
     HdfsFileStatusProto fs = convert(status.getDirStatus());
     SnapshottableDirectoryStatusProto.Builder builder =
         SnapshottableDirectoryStatusProto
-        .newBuilder().setSnapshotNumber(snapshotNumber)
+            .newBuilder()
-        .setSnapshotQuota(snapshotQuota).setParentFullpath(parentFullPathBytes)
+            .setSnapshotNumber(snapshotNumber)
-        .setDirStatus(fs);
+            .setSnapshotQuota(snapshotQuota)
+            .setParentFullpath(parentFullPathBytes)
+            .setDirStatus(fs);
     return builder.build();
   }
 
@@ -1816,14 +1819,15 @@ public class PBHelperClient {
       result.setRemaining(fsStats[ClientProtocol.GET_STATS_REMAINING_IDX]);
     if (fsStats.length >= ClientProtocol.GET_STATS_UNDER_REPLICATED_IDX + 1)
       result.setUnderReplicated(
-              fsStats[ClientProtocol.GET_STATS_UNDER_REPLICATED_IDX]);
+          fsStats[ClientProtocol.GET_STATS_UNDER_REPLICATED_IDX]);
     if (fsStats.length >= ClientProtocol.GET_STATS_CORRUPT_BLOCKS_IDX + 1)
       result.setCorruptBlocks(
           fsStats[ClientProtocol.GET_STATS_CORRUPT_BLOCKS_IDX]);
     if (fsStats.length >= ClientProtocol.GET_STATS_MISSING_BLOCKS_IDX + 1)
       result.setMissingBlocks(
           fsStats[ClientProtocol.GET_STATS_MISSING_BLOCKS_IDX]);
-    if (fsStats.length >= ClientProtocol.GET_STATS_MISSING_REPL_ONE_BLOCKS_IDX + 1)
+    if (fsStats.length >=
+        ClientProtocol.GET_STATS_MISSING_REPL_ONE_BLOCKS_IDX + 1)
       result.setMissingReplOneBlocks(
           fsStats[ClientProtocol.GET_STATS_MISSING_REPL_ONE_BLOCKS_IDX]);
     return result.build();
@@ -1901,7 +1905,7 @@ public class PBHelperClient {
   public static ContentSummaryProto convert(ContentSummary cs) {
     if (cs == null) return null;
     ContentSummaryProto.Builder builder = ContentSummaryProto.newBuilder();
-        builder.setLength(cs.getLength()).
+    builder.setLength(cs.getLength()).
         setFileCount(cs.getFileCount()).
         setDirectoryCount(cs.getDirectoryCount()).
         setQuota(cs.getQuota()).
@@ -1951,11 +1955,11 @@ public class PBHelperClient {
     return builder.build();
   }
 
-  public static List<StorageReportProto> convertStorageReports(StorageReport[] storages) {
+  public static List<StorageReportProto> convertStorageReports(
-    final List<StorageReportProto> protos = new ArrayList<StorageReportProto>(
+      StorageReport[] storages) {
-        storages.length);
+    final List<StorageReportProto> protos = new ArrayList<>(storages.length);
-    for(int i = 0; i < storages.length; i++) {
+    for (StorageReport storage : storages) {
-      protos.add(convert(storages[i]));
+      protos.add(convert(storage));
     }
     return protos;
   }
@@ -1978,17 +1982,16 @@ public class PBHelperClient {
     if (entry == null) {
       return null;
     }
-    ByteString sourcePath = ByteString
+    ByteString sourcePath = ByteString.copyFrom(entry.getSourcePath() == null ?
-        .copyFrom(entry.getSourcePath() == null ? DFSUtilClient.EMPTY_BYTES : entry
+        DFSUtilClient.EMPTY_BYTES : entry.getSourcePath());
-            .getSourcePath());
     String modification = entry.getType().getLabel();
     SnapshotDiffReportEntryProto.Builder builder = SnapshotDiffReportEntryProto
         .newBuilder().setFullpath(sourcePath)
         .setModificationLabel(modification);
     if (entry.getType() == DiffType.RENAME) {
-      ByteString targetPath = ByteString
+      ByteString targetPath =
-          .copyFrom(entry.getTargetPath() == null ? DFSUtilClient.EMPTY_BYTES : entry
+          ByteString.copyFrom(entry.getTargetPath() == null ?
-              .getTargetPath());
+              DFSUtilClient.EMPTY_BYTES : entry.getTargetPath());
       builder.setTargetPath(targetPath);
     }
     return builder.build();
@@ -2006,12 +2009,11 @@ public class PBHelperClient {
         entryProtos.add(entryProto);
     }
 
-    SnapshotDiffReportProto reportProto = SnapshotDiffReportProto.newBuilder()
+    return SnapshotDiffReportProto.newBuilder()
         .setSnapshotRoot(report.getSnapshotRoot())
         .setFromSnapshot(report.getFromSnapshot())
         .setToSnapshot(report.getLaterSnapshotName())
         .addAllDiffReportEntries(entryProtos).build();
-    return reportProto;
   }
 
   public static CacheDirectiveStatsProto convert(CacheDirectiveStats stats) {
@@ -2034,7 +2036,7 @@ public class PBHelperClient {
   }
 
   public static boolean[] convertBooleanList(
-    List<Boolean> targetPinningsList) {
+      List<Boolean> targetPinningsList) {
     final boolean[] targetPinnings = new boolean[targetPinningsList.size()];
     for (int i = 0; i < targetPinningsList.size(); i++) {
       targetPinnings[i] = targetPinningsList.get(i);
@@ -2060,7 +2062,8 @@ public class PBHelperClient {
   }
 
   public static DatanodeLocalInfoProto convert(DatanodeLocalInfo info) {
-    DatanodeLocalInfoProto.Builder builder = DatanodeLocalInfoProto.newBuilder();
+    DatanodeLocalInfoProto.Builder builder =
+        DatanodeLocalInfoProto.newBuilder();
     builder.setSoftwareVersion(info.getSoftwareVersion());
     builder.setConfigVersion(info.getConfigVersion());
     builder.setUptime(info.getUptime());
@@ -2116,9 +2119,9 @@ public class PBHelperClient {
   }
 
   public static ListXAttrsResponseProto convertListXAttrsResponse(
-    List<XAttr> names) {
+      List<XAttr> names) {
     ListXAttrsResponseProto.Builder builder =
-      ListXAttrsResponseProto.newBuilder();
+        ListXAttrsResponseProto.newBuilder();
     if (names != null) {
       builder.addAllXAttrs(convertXAttrProto(names));
     }
@@ -2140,114 +2143,115 @@ public class PBHelperClient {
         slotId.getSlotIdx());
   }
 
-  public static GetEditsFromTxidResponseProto convertEditsResponse(EventBatchList el) {
+  public static GetEditsFromTxidResponseProto convertEditsResponse(
+      EventBatchList el) {
     InotifyProtos.EventsListProto.Builder builder =
         InotifyProtos.EventsListProto.newBuilder();
     for (EventBatch b : el.getBatches()) {
       List<InotifyProtos.EventProto> events = Lists.newArrayList();
       for (Event e : b.getEvents()) {
         switch (e.getEventType()) {
-          case CLOSE:
+        case CLOSE:
-            Event.CloseEvent ce = (Event.CloseEvent) e;
+          Event.CloseEvent ce = (Event.CloseEvent) e;
-            events.add(InotifyProtos.EventProto.newBuilder()
+          events.add(InotifyProtos.EventProto.newBuilder()
-                .setType(InotifyProtos.EventType.EVENT_CLOSE)
+              .setType(InotifyProtos.EventType.EVENT_CLOSE)
-                .setContents(
+              .setContents(
-                    InotifyProtos.CloseEventProto.newBuilder()
+                  InotifyProtos.CloseEventProto.newBuilder()
-                        .setPath(ce.getPath())
+                      .setPath(ce.getPath())
-                        .setFileSize(ce.getFileSize())
+                      .setFileSize(ce.getFileSize())
-                        .setTimestamp(ce.getTimestamp()).build().toByteString()
+                      .setTimestamp(ce.getTimestamp()).build().toByteString()
-                ).build());
+              ).build());
-            break;
+          break;
-          case CREATE:
+        case CREATE:
-            Event.CreateEvent ce2 = (Event.CreateEvent) e;
+          Event.CreateEvent ce2 = (Event.CreateEvent) e;
-            events.add(InotifyProtos.EventProto.newBuilder()
+          events.add(InotifyProtos.EventProto.newBuilder()
-                .setType(InotifyProtos.EventType.EVENT_CREATE)
+              .setType(InotifyProtos.EventType.EVENT_CREATE)
-                .setContents(
+              .setContents(
-                    InotifyProtos.CreateEventProto.newBuilder()
+                  InotifyProtos.CreateEventProto.newBuilder()
-                        .setType(createTypeConvert(ce2.getiNodeType()))
+                      .setType(createTypeConvert(ce2.getiNodeType()))
-                        .setPath(ce2.getPath())
+                      .setPath(ce2.getPath())
-                        .setCtime(ce2.getCtime())
+                      .setCtime(ce2.getCtime())
-                        .setOwnerName(ce2.getOwnerName())
+                      .setOwnerName(ce2.getOwnerName())
-                        .setGroupName(ce2.getGroupName())
+                      .setGroupName(ce2.getGroupName())
-                        .setPerms(convert(ce2.getPerms()))
+                      .setPerms(convert(ce2.getPerms()))
-                        .setReplication(ce2.getReplication())
+                      .setReplication(ce2.getReplication())
-                        .setSymlinkTarget(ce2.getSymlinkTarget() == null ?
+                      .setSymlinkTarget(ce2.getSymlinkTarget() == null ?
-                            "" : ce2.getSymlinkTarget())
+                          "" : ce2.getSymlinkTarget())
-                        .setDefaultBlockSize(ce2.getDefaultBlockSize())
+                      .setDefaultBlockSize(ce2.getDefaultBlockSize())
-                        .setOverwrite(ce2.getOverwrite()).build().toByteString()
+                      .setOverwrite(ce2.getOverwrite()).build().toByteString()
-                ).build());
+              ).build());
-            break;
+          break;
-          case METADATA:
+        case METADATA:
-            Event.MetadataUpdateEvent me = (Event.MetadataUpdateEvent) e;
+          Event.MetadataUpdateEvent me = (Event.MetadataUpdateEvent) e;
-            InotifyProtos.MetadataUpdateEventProto.Builder metaB =
+          InotifyProtos.MetadataUpdateEventProto.Builder metaB =
-                InotifyProtos.MetadataUpdateEventProto.newBuilder()
+              InotifyProtos.MetadataUpdateEventProto.newBuilder()
-                    .setPath(me.getPath())
+                  .setPath(me.getPath())
-                    .setType(metadataUpdateTypeConvert(me.getMetadataType()))
+                  .setType(metadataUpdateTypeConvert(me.getMetadataType()))
-                    .setMtime(me.getMtime())
+                  .setMtime(me.getMtime())
-                    .setAtime(me.getAtime())
+                  .setAtime(me.getAtime())
-                    .setReplication(me.getReplication())
+                  .setReplication(me.getReplication())
-                    .setOwnerName(me.getOwnerName() == null ? "" :
+                  .setOwnerName(me.getOwnerName() == null ? "" :
-                        me.getOwnerName())
+                      me.getOwnerName())
-                    .setGroupName(me.getGroupName() == null ? "" :
+                  .setGroupName(me.getGroupName() == null ? "" :
-                        me.getGroupName())
+                      me.getGroupName())
-                    .addAllAcls(me.getAcls() == null ?
+                  .addAllAcls(me.getAcls() == null ?
-                        Lists.<AclEntryProto>newArrayList() :
+                      Lists.<AclEntryProto>newArrayList() :
-                        convertAclEntryProto(me.getAcls()))
+                      convertAclEntryProto(me.getAcls()))
-                    .addAllXAttrs(me.getxAttrs() == null ?
+                  .addAllXAttrs(me.getxAttrs() == null ?
-                        Lists.<XAttrProto>newArrayList() :
+                      Lists.<XAttrProto>newArrayList() :
-                        convertXAttrProto(me.getxAttrs()))
+                      convertXAttrProto(me.getxAttrs()))
-                    .setXAttrsRemoved(me.isxAttrsRemoved());
+                  .setXAttrsRemoved(me.isxAttrsRemoved());
-            if (me.getPerms() != null) {
+          if (me.getPerms() != null) {
-              metaB.setPerms(convert(me.getPerms()));
+            metaB.setPerms(convert(me.getPerms()));
-            }
+          }
-            events.add(InotifyProtos.EventProto.newBuilder()
+          events.add(InotifyProtos.EventProto.newBuilder()
-                .setType(InotifyProtos.EventType.EVENT_METADATA)
+              .setType(InotifyProtos.EventType.EVENT_METADATA)
-                .setContents(metaB.build().toByteString())
+              .setContents(metaB.build().toByteString())
-                .build());
+              .build());
-            break;
+          break;
-          case RENAME:
+        case RENAME:
-            Event.RenameEvent re = (Event.RenameEvent) e;
+          Event.RenameEvent re = (Event.RenameEvent) e;
-            events.add(InotifyProtos.EventProto.newBuilder()
+          events.add(InotifyProtos.EventProto.newBuilder()
-                .setType(InotifyProtos.EventType.EVENT_RENAME)
+              .setType(InotifyProtos.EventType.EVENT_RENAME)
-                .setContents(
+              .setContents(
-                    InotifyProtos.RenameEventProto.newBuilder()
+                  InotifyProtos.RenameEventProto.newBuilder()
-                        .setSrcPath(re.getSrcPath())
+                      .setSrcPath(re.getSrcPath())
-                        .setDestPath(re.getDstPath())
+                      .setDestPath(re.getDstPath())
-                        .setTimestamp(re.getTimestamp()).build().toByteString()
+                      .setTimestamp(re.getTimestamp()).build().toByteString()
-                ).build());
+              ).build());
-            break;
+          break;
-          case APPEND:
+        case APPEND:
-            Event.AppendEvent re2 = (Event.AppendEvent) e;
+          Event.AppendEvent re2 = (Event.AppendEvent) e;
-            events.add(InotifyProtos.EventProto.newBuilder()
+          events.add(InotifyProtos.EventProto.newBuilder()
-                .setType(InotifyProtos.EventType.EVENT_APPEND)
+              .setType(InotifyProtos.EventType.EVENT_APPEND)
-                .setContents(InotifyProtos.AppendEventProto.newBuilder()
+              .setContents(InotifyProtos.AppendEventProto.newBuilder()
-                    .setPath(re2.getPath())
+                  .setPath(re2.getPath())
-                    .setNewBlock(re2.toNewBlock()).build().toByteString())
+                  .setNewBlock(re2.toNewBlock()).build().toByteString())
-                .build());
+              .build());
-            break;
+          break;
-          case UNLINK:
+        case UNLINK:
-            Event.UnlinkEvent ue = (Event.UnlinkEvent) e;
+          Event.UnlinkEvent ue = (Event.UnlinkEvent) e;
-            events.add(InotifyProtos.EventProto.newBuilder()
+          events.add(InotifyProtos.EventProto.newBuilder()
-                .setType(InotifyProtos.EventType.EVENT_UNLINK)
+              .setType(InotifyProtos.EventType.EVENT_UNLINK)
-                .setContents(
+              .setContents(
-                    InotifyProtos.UnlinkEventProto.newBuilder()
+                  InotifyProtos.UnlinkEventProto.newBuilder()
-                        .setPath(ue.getPath())
+                      .setPath(ue.getPath())
-                        .setTimestamp(ue.getTimestamp()).build().toByteString()
+                      .setTimestamp(ue.getTimestamp()).build().toByteString()
-                ).build());
+              ).build());
-            break;
+          break;
-          case TRUNCATE:
+        case TRUNCATE:
-            Event.TruncateEvent te = (Event.TruncateEvent) e;
+          Event.TruncateEvent te = (Event.TruncateEvent) e;
-            events.add(InotifyProtos.EventProto.newBuilder()
+          events.add(InotifyProtos.EventProto.newBuilder()
-                .setType(InotifyProtos.EventType.EVENT_TRUNCATE)
+              .setType(InotifyProtos.EventType.EVENT_TRUNCATE)
-                .setContents(
+              .setContents(
-                    InotifyProtos.TruncateEventProto.newBuilder()
+                  InotifyProtos.TruncateEventProto.newBuilder()
-                        .setPath(te.getPath())
+                      .setPath(te.getPath())
-                        .setFileSize(te.getFileSize())
+                      .setFileSize(te.getFileSize())
-                        .setTimestamp(te.getTimestamp()).build().toByteString()
+                      .setTimestamp(te.getTimestamp()).build().toByteString()
-                ).build());
+              ).build());
-            break;
+          break;
-          default:
+        default:
-            throw new RuntimeException("Unexpected inotify event: " + e);
+          throw new RuntimeException("Unexpected inotify event: " + e);
         }
       }
       builder.addBatch(InotifyProtos.EventBatchProto.newBuilder().

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/security/token/delegation/DelegationTokenIdentifier.java

@@ -34,7 +34,8 @@ import org.apache.hadoop.security.token.delegation.AbstractDelegationTokenIdenti
 @InterfaceAudience.Private
 public class DelegationTokenIdentifier
     extends AbstractDelegationTokenIdentifier {
-  public static final Text HDFS_DELEGATION_KIND = new Text("HDFS_DELEGATION_TOKEN");
+  public static final Text HDFS_DELEGATION_KIND =
+      new Text("HDFS_DELEGATION_TOKEN");
 
   /**
    * Create an empty delegation token identifier for reading into.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/server/datanode/BlockMetadataHeader.java

@@ -137,7 +137,8 @@ public class BlockMetadataHeader {
    * @return Metadata Header
    * @throws IOException
    */
-  public static BlockMetadataHeader readHeader(DataInputStream in) throws IOException {
+  public static BlockMetadataHeader readHeader(DataInputStream in)
+      throws IOException {
     return readHeader(in.readShort(), in);
   }
 
@@ -163,7 +164,8 @@ public class BlockMetadataHeader {
    * The current file position will be altered by this method.
    * If an error occurs, the file is <em>not</em> closed.
    */
-  public static BlockMetadataHeader readHeader(RandomAccessFile raf) throws IOException {
+  public static BlockMetadataHeader readHeader(RandomAccessFile raf)
+      throws IOException {
     byte[] buf = new byte[getHeaderSize()];
     raf.seek(0);
     raf.readFully(buf, 0, buf.length);
@@ -171,8 +173,8 @@ public class BlockMetadataHeader {
   }
 
   // Version is already read.
-  private static BlockMetadataHeader readHeader(short version, DataInputStream in) 
+  private static BlockMetadataHeader readHeader(short version,
-                                   throws IOException {
+      DataInputStream in) throws IOException {
     DataChecksum checksum = DataChecksum.newDataChecksum(in);
     return new BlockMetadataHeader(version, checksum);
   }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/server/datanode/ReplicaNotFoundException.java

@@ -29,15 +29,17 @@ import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
  */
 public class ReplicaNotFoundException extends IOException {
   private static final long serialVersionUID = 1L;
-  public final static String NON_RBW_REPLICA = "Cannot recover a non-RBW replica ";
+  public final static String NON_RBW_REPLICA =
+      "Cannot recover a non-RBW replica ";
   public final static String UNFINALIZED_REPLICA =
-    "Cannot append to an unfinalized replica ";
+      "Cannot append to an unfinalized replica ";
   public final static String UNFINALIZED_AND_NONRBW_REPLICA =
-    "Cannot recover append/close to a replica that's not FINALIZED and not RBW ";
+      "Cannot recover append/close to a replica that's not FINALIZED and not RBW"
+          + " ";
   public final static String NON_EXISTENT_REPLICA =
-    "Cannot append to a non-existent replica ";
+      "Cannot append to a non-existent replica ";
   public final static String UNEXPECTED_GS_REPLICA =
-    "Cannot append to a replica with unexpected generation stamp ";
+      "Cannot append to a replica with unexpected generation stamp ";
 
   public ReplicaNotFoundException() {
     super();

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/server/namenode/ha/AbstractNNFailoverProxyProvider.java

@@ -20,11 +20,10 @@ package org.apache.hadoop.hdfs.server.namenode.ha;
 
 import java.util.concurrent.atomic.AtomicBoolean;
 
-import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.io.retry.FailoverProxyProvider;
 
 public abstract class AbstractNNFailoverProxyProvider<T> implements
-   FailoverProxyProvider <T> {
+    FailoverProxyProvider <T> {
 
   private AtomicBoolean fallbackToSimpleAuth;
 

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/server/protocol/DatanodeStorage.java

@@ -30,18 +30,20 @@ public class DatanodeStorage {
     NORMAL,
 
     /**
-     * A storage that represents a read-only path to replicas stored on a shared storage device.
+     * A storage that represents a read-only path to replicas stored on a shared
-     * Replicas on {@link #READ_ONLY_SHARED} storage are not counted towards live replicas.
+     * storage device. Replicas on {@link #READ_ONLY_SHARED} storage are not
+     * counted towards live replicas.
      *
      * <p>
-     * In certain implementations, a {@link #READ_ONLY_SHARED} storage may be correlated to 
+     * In certain implementations, a {@link #READ_ONLY_SHARED} storage may be
-     * its {@link #NORMAL} counterpart using the {@link DatanodeStorage#storageID}.  This
+     * correlated to its {@link #NORMAL} counterpart using the
-     * property should be used for debugging purposes only.
+     * {@link DatanodeStorage#storageID}.  This property should be used for
+     * debugging purposes only.
      * </p>
      */
     READ_ONLY_SHARED,
 
-    FAILED;
+    FAILED
   }
 
   private final String storageID;
@@ -91,10 +93,9 @@ public class DatanodeStorage {
     try {
       // Attempt to parse the UUID.
       if (storageID != null && storageID.indexOf(STORAGE_ID_PREFIX) == 0) {
-        UUID.fromString(storageID.substring(STORAGE_ID_PREFIX.length()));
         return true;
       }
-    } catch (IllegalArgumentException iae) {
+    } catch (IllegalArgumentException ignored) {
     }
 
     return false;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/shortcircuit/DfsClientShmManager.java

@@ -52,13 +52,14 @@ import org.slf4j.LoggerFactory;
 /**
  * Manages short-circuit memory segments for an HDFS client.
  *
- * Clients are responsible for requesting and releasing shared memory segments used
+ * Clients are responsible for requesting and releasing shared memory segments
- * for communicating with the DataNode. The client will try to allocate new slots
+ * used for communicating with the DataNode. The client will try to allocate new
- * in the set of existing segments, falling back to getting a new segment from the
+ * slots in the set of existing segments, falling back to getting a new segment
- * DataNode via {@link DataTransferProtocol#requestShortCircuitFds}.
+ * from the DataNode via {@link DataTransferProtocol#requestShortCircuitFds}.
  *
- * The counterpart to this class on the DataNode is {@link ShortCircuitRegistry}.
+ * The counterpart to this class on the DataNode is
- * See {@link ShortCircuitRegistry} for more information on the communication protocol.
+ * {@link ShortCircuitRegistry}. See {@link ShortCircuitRegistry} for more
+ * information on the communication protocol.
  */
 @InterfaceAudience.Private
 public class DfsClientShmManager implements Closeable {
@@ -79,16 +80,14 @@ public class DfsClientShmManager implements Closeable {
      *
      * Protected by the manager lock.
      */
-    private final TreeMap<ShmId, DfsClientShm> full =
+    private final TreeMap<ShmId, DfsClientShm> full = new TreeMap<>();
-        new TreeMap<ShmId, DfsClientShm>();
 
     /**
      * Shared memory segments which have at least one empty slot.
      *
      * Protected by the manager lock.
      */
-    private final TreeMap<ShmId, DfsClientShm> notFull =
+    private final TreeMap<ShmId, DfsClientShm> notFull = new TreeMap<>();
-        new TreeMap<ShmId, DfsClientShm>();
 
     /**
      * True if this datanode doesn't support short-circuit shared memory
@@ -383,7 +382,7 @@ public class DfsClientShmManager implements Closeable {
    * Information about each Datanode.
    */
   private final HashMap<DatanodeInfo, EndpointShmManager> datanodes =
-      new HashMap<DatanodeInfo, EndpointShmManager>(1);
+      new HashMap<>(1);
 
   /**
    * The DomainSocketWatcher which keeps track of the UNIX domain socket
@@ -456,8 +455,7 @@ public class DfsClientShmManager implements Closeable {
   public void visit(Visitor visitor) throws IOException {
     lock.lock();
     try {
-      HashMap<DatanodeInfo, PerDatanodeVisitorInfo> info = 
+      HashMap<DatanodeInfo, PerDatanodeVisitorInfo> info = new HashMap<>();
-          new HashMap<DatanodeInfo, PerDatanodeVisitorInfo>();
       for (Entry<DatanodeInfo, EndpointShmManager> entry :
             datanodes.entrySet()) {
         info.put(entry.getKey(), entry.getValue().getVisitorInfo());

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/shortcircuit/DomainSocketFactory.java

@@ -85,8 +85,7 @@ public class DomainSocketFactory {
 
     @Override
     public String toString() {
-      return new StringBuilder().append("PathInfo{path=").append(path).
+      return "PathInfo{path=" + path + ", state=" + state + "}";
-          append(", state=").append(state).append("}").toString();
     }
   }
 

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/shortcircuit/ShortCircuitCache.java

@@ -107,7 +107,7 @@ public class ShortCircuitCache implements Closeable {
 
         int numDemoted = demoteOldEvictableMmaped(curMs);
         int numPurged = 0;
-        Long evictionTimeNs = Long.valueOf(0);
+        Long evictionTimeNs = (long) 0;
         while (true) {
           Entry<Long, ShortCircuitReplica> entry =
               evictable.ceilingEntry(evictionTimeNs);
@@ -119,14 +119,14 @@ public class ShortCircuitCache implements Closeable {
           ShortCircuitReplica replica = entry.getValue();
           if (LOG.isTraceEnabled()) {
             LOG.trace("CacheCleaner: purging " + replica + ": " +
-                  StringUtils.getStackTrace(Thread.currentThread()));
+                StringUtils.getStackTrace(Thread.currentThread()));
           }
           purge(replica);
           numPurged++;
         }
 
         LOG.debug("{}: finishing cache cleaner run started at {}. Demoted {} "
-            + "mmapped replicas; purged {} replicas.",
+                + "mmapped replicas; purged {} replicas.",
             this, curMs, numDemoted, numPurged);
       } finally {
         ShortCircuitCache.this.lock.unlock();
@@ -236,17 +236,17 @@ public class ShortCircuitCache implements Closeable {
    * The executor service that runs the cacheCleaner.
    */
   private final ScheduledThreadPoolExecutor cleanerExecutor
-  = new ScheduledThreadPoolExecutor(1, new ThreadFactoryBuilder().
+      = new ScheduledThreadPoolExecutor(1, new ThreadFactoryBuilder().
-          setDaemon(true).setNameFormat("ShortCircuitCache_Cleaner").
+      setDaemon(true).setNameFormat("ShortCircuitCache_Cleaner").
-          build());
+      build());
 
   /**
    * The executor service that runs the cacheCleaner.
    */
   private final ScheduledThreadPoolExecutor releaserExecutor
       = new ScheduledThreadPoolExecutor(1, new ThreadFactoryBuilder().
-          setDaemon(true).setNameFormat("ShortCircuitCache_SlotReleaser").
+      setDaemon(true).setNameFormat("ShortCircuitCache_SlotReleaser").
-          build());
+      build());
 
   /**
    * A map containing all ShortCircuitReplicaInfo objects, organized by Key.
@@ -254,8 +254,7 @@ public class ShortCircuitCache implements Closeable {
    * exception.
    */
   private final HashMap<ExtendedBlockId, Waitable<ShortCircuitReplicaInfo>>
-      replicaInfoMap = new HashMap<ExtendedBlockId,
+      replicaInfoMap = new HashMap<>();
-          Waitable<ShortCircuitReplicaInfo>>();
 
   /**
    * The CacheCleaner.  We don't create this and schedule it until it becomes
@@ -268,8 +267,7 @@ public class ShortCircuitCache implements Closeable {
    *
    * Maps (unique) insertion time in nanoseconds to the element.
    */
-  private final TreeMap<Long, ShortCircuitReplica> evictable =
+  private final TreeMap<Long, ShortCircuitReplica> evictable = new TreeMap<>();
-      new TreeMap<Long, ShortCircuitReplica>();
 
   /**
    * Maximum total size of the cache, including both mmapped and
@@ -288,7 +286,7 @@ public class ShortCircuitCache implements Closeable {
    * Maps (unique) insertion time in nanoseconds to the element.
    */
   private final TreeMap<Long, ShortCircuitReplica> evictableMmapped =
-      new TreeMap<Long, ShortCircuitReplica>();
+      new TreeMap<>();
 
   /**
    * Maximum number of mmaped evictable elements.
@@ -435,13 +433,13 @@ public class ShortCircuitCache implements Closeable {
       if (newRefCount == 0) {
         // Close replica, since there are no remaining references to it.
         Preconditions.checkArgument(replica.purged,
-          "Replica %s reached a refCount of 0 without being purged", replica);
+            "Replica %s reached a refCount of 0 without being purged", replica);
         replica.close();
       } else if (newRefCount == 1) {
         Preconditions.checkState(null == replica.getEvictableTimeNs(),
             "Replica %s had a refCount higher than 1, " +
-              "but was still evictable (evictableTimeNs = %d)",
+                "but was still evictable (evictableTimeNs = %d)",
-              replica, replica.getEvictableTimeNs());
+            replica, replica.getEvictableTimeNs());
         if (!replica.purged) {
           // Add the replica to the end of an eviction list.
           // Eviction lists are sorted by time.
@@ -457,7 +455,7 @@ public class ShortCircuitCache implements Closeable {
       } else {
         Preconditions.checkArgument(replica.refCount >= 0,
             "replica's refCount went negative (refCount = %d" +
-            " for %s)", replica.refCount, replica);
+                " for %s)", replica.refCount, replica);
       }
       if (LOG.isTraceEnabled()) {
         LOG.trace(this + ": unref replica " + replica +
@@ -484,7 +482,7 @@ public class ShortCircuitCache implements Closeable {
   private int demoteOldEvictableMmaped(long now) {
     int numDemoted = 0;
     boolean needMoreSpace = false;
-    Long evictionTimeNs = Long.valueOf(0);
+    Long evictionTimeNs = (long) 0;
 
     while (true) {
       Entry<Long, ShortCircuitReplica> entry =
@@ -530,13 +528,13 @@ public class ShortCircuitCache implements Closeable {
       }
       ShortCircuitReplica replica;
       if (evictableSize == 0) {
-       replica = evictableMmapped.firstEntry().getValue();
+        replica = evictableMmapped.firstEntry().getValue();
       } else {
-       replica = evictable.firstEntry().getValue();
+        replica = evictable.firstEntry().getValue();
       }
       if (LOG.isTraceEnabled()) {
         LOG.trace(this + ": trimEvictionMaps is purging " + replica +
-          StringUtils.getStackTrace(Thread.currentThread()));
+            StringUtils.getStackTrace(Thread.currentThread()));
       }
       purge(replica);
     }
@@ -677,13 +675,12 @@ public class ShortCircuitCache implements Closeable {
             info = fetch(key, waitable);
           } catch (RetriableException e) {
             LOG.debug("{}: retrying {}", this, e.getMessage());
-            continue;
           }
         }
       } while (false);
       if (info != null) return info;
       // We need to load the replica ourselves.
-      newWaitable = new Waitable<ShortCircuitReplicaInfo>(lock.newCondition());
+      newWaitable = new Waitable<>(lock.newCondition());
       replicaInfoMap.put(key, newWaitable);
     } finally {
       lock.unlock();
@@ -716,7 +713,7 @@ public class ShortCircuitCache implements Closeable {
     }
     if (info.getInvalidTokenException() != null) {
       LOG.info(this + ": could not get " + key + " due to InvalidToken " +
-            "exception.", info.getInvalidTokenException());
+          "exception.", info.getInvalidTokenException());
       return info;
     }
     ShortCircuitReplica replica = info.getReplica();
@@ -833,7 +830,7 @@ public class ShortCircuitCache implements Closeable {
     lock.lock();
     try {
       if (map == null) {
-        replica.mmapData = Long.valueOf(Time.monotonicNow());
+        replica.mmapData = Time.monotonicNow();
         newCond.signalAll();
         return null;
       } else {
@@ -920,12 +917,10 @@ public class ShortCircuitCache implements Closeable {
   public void accept(CacheVisitor visitor) {
     lock.lock();
     try {
-      Map<ExtendedBlockId, ShortCircuitReplica> replicas =
+      Map<ExtendedBlockId, ShortCircuitReplica> replicas = new HashMap<>();
-          new HashMap<ExtendedBlockId, ShortCircuitReplica>();
+      Map<ExtendedBlockId, InvalidToken> failedLoads = new HashMap<>();
-      Map<ExtendedBlockId, InvalidToken> failedLoads =
-          new HashMap<ExtendedBlockId, InvalidToken>();
       for (Entry<ExtendedBlockId, Waitable<ShortCircuitReplicaInfo>> entry :
-            replicaInfoMap.entrySet()) {
+          replicaInfoMap.entrySet()) {
         Waitable<ShortCircuitReplicaInfo> waitable = entry.getValue();
         if (waitable.hasVal()) {
           if (waitable.getVal().getReplica() != null) {
@@ -939,11 +934,11 @@ public class ShortCircuitCache implements Closeable {
         }
       }
       LOG.debug("visiting {} with outstandingMmapCount={}, replicas={}, "
-          + "failedLoads={}, evictable={}, evictableMmapped={}",
+              + "failedLoads={}, evictable={}, evictableMmapped={}",
           visitor.getClass().getName(), outstandingMmapCount, replicas,
           failedLoads, evictable, evictableMmapped);
       visitor.visit(outstandingMmapCount, replicas, failedLoads,
-            evictable, evictableMmapped);
+          evictable, evictableMmapped);
     } finally {
       lock.unlock();
     }
@@ -971,8 +966,8 @@ public class ShortCircuitCache implements Closeable {
    *                         the datanode.
    */
   public Slot allocShmSlot(DatanodeInfo datanode,
-        DomainPeer peer, MutableBoolean usedPeer,
+      DomainPeer peer, MutableBoolean usedPeer,
-        ExtendedBlockId blockId, String clientName) throws IOException {
+      ExtendedBlockId blockId, String clientName) throws IOException {
     if (shmManager != null) {
       return shmManager.allocSlot(datanode, peer, usedPeer,
           blockId, clientName);

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/shortcircuit/ShortCircuitReplica.java

@@ -28,7 +28,6 @@ import org.apache.hadoop.hdfs.ExtendedBlockId;
 import org.apache.hadoop.hdfs.server.datanode.BlockMetadataHeader;
 import org.apache.hadoop.hdfs.shortcircuit.ShortCircuitShm.Slot;
 import org.apache.hadoop.hdfs.util.IOUtilsClient;
-import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.io.nativeio.NativeIO;
 import org.apache.hadoop.util.Time;
 
@@ -325,13 +324,10 @@ public class ShortCircuitReplica {
    */
   @Override
   public String toString() {
-    return new StringBuilder().append("ShortCircuitReplica{").
+    return "ShortCircuitReplica{" + "key=" + key
-        append("key=").append(key).
+        + ", metaHeader.version=" + metaHeader.getVersion()
-        append(", metaHeader.version=").append(metaHeader.getVersion()).
+        + ", metaHeader.checksum=" + metaHeader.getChecksum()
-        append(", metaHeader.checksum=").append(metaHeader.getChecksum()).
+        + ", ident=" + "0x" + Integer.toHexString(System.identityHashCode(this))
-        append(", ident=").append("0x").
+        + ", creationTimeMs=" + creationTimeMs + "}";
-          append(Integer.toHexString(System.identityHashCode(this))).
-        append(", creationTimeMs=").append(creationTimeMs).
-        append("}").toString();
   }
 }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/shortcircuit/ShortCircuitReplicaInfo.java

@@ -56,7 +56,6 @@ public final class ShortCircuitReplicaInfo {
     }
     if (exc != null) {
       builder.append(prefix).append(exc);
-      prefix = ", ";
     }
     builder.append("}");
     return builder.toString();

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/shortcircuit/ShortCircuitShm.java

@@ -43,11 +43,14 @@ import com.google.common.base.Preconditions;
 import com.google.common.collect.ComparisonChain;
 import com.google.common.primitives.Ints;
 
+import javax.annotation.Nonnull;
+
 /**
  * A shared memory segment used to implement short-circuit reads.
  */
 public class ShortCircuitShm {
-  private static final Logger LOG = LoggerFactory.getLogger(ShortCircuitShm.class);
+  private static final Logger LOG = LoggerFactory.getLogger(
+      ShortCircuitShm.class);
 
   protected static final int BYTES_PER_SLOT = 64;
 
@@ -140,13 +143,13 @@ public class ShortCircuitShm {
     }
 
     @Override
-    public int compareTo(ShmId other) {
+    public int compareTo(@Nonnull ShmId other) {
       return ComparisonChain.start().
           compare(hi, other.hi).
           compare(lo, other.lo).
           result();
     }
-  };
+  }
 
   /**
    * Uniquely identifies a slot.
@@ -367,11 +370,8 @@ public class ShortCircuitShm {
 
     public boolean isAnchored() {
       long prev = unsafe.getLongVolatile(null, this.slotAddress);
-      if ((prev & VALID_FLAG) == 0) {
+      // Slot is no longer valid.
-        // Slot is no longer valid.
+      return (prev & VALID_FLAG) != 0 && ((prev & 0x7fffffff) != 0);
-        return false;
-      }
-      return ((prev & 0x7fffffff) != 0);
     }
 
     /**
@@ -517,7 +517,7 @@ public class ShortCircuitShm {
    * @param slotIdx   Index of the slot.
    * @return          The base address of the slot.
    */
-  private final long calculateSlotAddress(int slotIdx) {
+  private long calculateSlotAddress(int slotIdx) {
     long offset = slotIdx;
     offset *= BYTES_PER_SLOT;
     return this.baseAddress + offset;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/util/ExactSizeInputStream.java

@@ -27,6 +27,8 @@ import org.apache.hadoop.classification.InterfaceStability;
 
 import com.google.common.base.Preconditions;
 
+import javax.annotation.Nonnull;
+
 /**
  * An InputStream implementations which reads from some other InputStream
  * but expects an exact number of bytes. Any attempts to read past the
@@ -80,7 +82,7 @@ public class ExactSizeInputStream extends FilterInputStream {
   }
 
   @Override
-  public int read(final byte[] b, final int off, int len)
+  public int read(@Nonnull final byte[] b, final int off, int len)
                   throws IOException {
     if (remaining <= 0) {
       return -1;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/util/LongBitFormat.java

@@ -38,7 +38,8 @@ public class LongBitFormat implements Serializable {
   /** Bit mask */
   private final long MASK;
 
-  public LongBitFormat(String name, LongBitFormat previous, int length, long min) {
+  public LongBitFormat(String name, LongBitFormat previous, int length,
+                       long min) {
     NAME = name;
     OFFSET = previous == null? 0: previous.OFFSET + previous.LENGTH;
     LENGTH = length;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/ByteRangeInputStream.java

@@ -34,6 +34,8 @@ import org.apache.http.HttpStatus;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.net.HttpHeaders;
 
+import javax.annotation.Nonnull;
+
 /**
  * To support HTTP byte streams, a new connection to an HTTP server needs to be
  * created each time. This class hides the complexity of those multiple
@@ -102,24 +104,24 @@ public abstract class ByteRangeInputStream extends FSInputStream {
   }
 
   protected abstract URL getResolvedUrl(final HttpURLConnection connection
-      ) throws IOException;
+  ) throws IOException;
 
   @VisibleForTesting
   protected InputStream getInputStream() throws IOException {
     switch (status) {
-      case NORMAL:
+    case NORMAL:
-        break;
+      break;
-      case SEEK:
+    case SEEK:
-        if (in != null) {
+      if (in != null) {
-          in.close();
+        in.close();
-        }
+      }
-        InputStreamAndFileLength fin = openInputStream(startPos);
+      InputStreamAndFileLength fin = openInputStream(startPos);
-        in = fin.in;
+      in = fin.in;
-        fileLength = fin.length;
+      fileLength = fin.length;
-        status = StreamStatus.NORMAL;
+      status = StreamStatus.NORMAL;
-        break;
+      break;
-      case CLOSED:
+    case CLOSED:
-        throw new IOException("Stream closed");
+      throw new IOException("Stream closed");
     }
     return in;
   }
@@ -225,7 +227,7 @@ public abstract class ByteRangeInputStream extends FSInputStream {
   }
 
   @Override
-  public int read(byte b[], int off, int len) throws IOException {
+  public int read(@Nonnull byte b[], int off, int len) throws IOException {
     return update(getInputStream().read(b, off, len));
   }
 

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/JsonUtilClient.java

@@ -60,7 +60,8 @@ class JsonUtilClient {
 
   /** Convert a Json map to a RemoteException. */
   static RemoteException toRemoteException(final Map<?, ?> json) {
-    final Map<?, ?> m = (Map<?, ?>)json.get(RemoteException.class.getSimpleName());
+    final Map<?, ?> m = (Map<?, ?>)json.get(
+        RemoteException.class.getSimpleName());
     final String message = (String)m.get("message");
     final String javaClassName = (String)m.get("javaClassName");
     return new RemoteException(javaClassName, message);
@@ -100,7 +101,8 @@ class JsonUtilClient {
   }
 
   /** Convert a Json map to a HdfsFileStatus object. */
-  static HdfsFileStatus toFileStatus(final Map<?, ?> json, boolean includesType) {
+  static HdfsFileStatus toFileStatus(final Map<?, ?> json,
+      boolean includesType) {
     if (json == null) {
       return null;
     }
@@ -108,7 +110,8 @@ class JsonUtilClient {
     final Map<?, ?> m = includesType ?
         (Map<?, ?>)json.get(FileStatus.class.getSimpleName()) : json;
     final String localName = (String) m.get("pathSuffix");
-    final WebHdfsConstants.PathType type = WebHdfsConstants.PathType.valueOf((String) m.get("type"));
+    final WebHdfsConstants.PathType type =
+        WebHdfsConstants.PathType.valueOf((String) m.get("type"));
     final byte[] symlink = type != WebHdfsConstants.PathType.SYMLINK? null
         : DFSUtilClient.string2Bytes((String) m.get("symlink"));
 
@@ -116,20 +119,21 @@ class JsonUtilClient {
     final String owner = (String) m.get("owner");
     final String group = (String) m.get("group");
     final FsPermission permission = toFsPermission((String) m.get("permission"),
-                                                   (Boolean) m.get("aclBit"),
+        (Boolean) m.get("aclBit"),
-                                                   (Boolean) m.get("encBit"));
+        (Boolean) m.get("encBit"));
     final long aTime = ((Number) m.get("accessTime")).longValue();
     final long mTime = ((Number) m.get("modificationTime")).longValue();
     final long blockSize = ((Number) m.get("blockSize")).longValue();
     final short replication = ((Number) m.get("replication")).shortValue();
     final long fileId = m.containsKey("fileId") ?
-        ((Number) m.get("fileId")).longValue() : HdfsConstants.GRANDFATHER_INODE_ID;
+        ((Number) m.get("fileId")).longValue() :
+        HdfsConstants.GRANDFATHER_INODE_ID;
     final int childrenNum = getInt(m, "childrenNum", -1);
     final byte storagePolicy = m.containsKey("storagePolicy") ?
         (byte) ((Number) m.get("storagePolicy")).longValue() :
         HdfsConstants.BLOCK_STORAGE_POLICY_ID_UNSPECIFIED;
-    return new HdfsFileStatus(len, type == WebHdfsConstants.PathType.DIRECTORY, replication,
+    return new HdfsFileStatus(len, type == WebHdfsConstants.PathType.DIRECTORY,
-        blockSize, mTime, aTime, permission, owner, group,
+        replication, blockSize, mTime, aTime, permission, owner, group,
         symlink, DFSUtilClient.string2Bytes(localName),
         fileId, childrenNum, null,
         storagePolicy);
@@ -185,7 +189,7 @@ class JsonUtilClient {
 
   /** Convert a Json map to an DatanodeInfo object. */
   static DatanodeInfo toDatanodeInfo(final Map<?, ?> m)
-    throws IOException {
+      throws IOException {
     if (m == null) {
       return null;
     }
@@ -304,7 +308,8 @@ class JsonUtilClient {
       return null;
     }
 
-    final Map<?, ?> m = (Map<?, ?>)json.get(ContentSummary.class.getSimpleName());
+    final Map<?, ?> m = (Map<?, ?>)json.get(
+        ContentSummary.class.getSimpleName());
     final long length = ((Number) m.get("length")).longValue();
     final long fileCount = ((Number) m.get("fileCount")).longValue();
     final long directoryCount = ((Number) m.get("directoryCount")).longValue();
@@ -312,9 +317,13 @@ class JsonUtilClient {
     final long spaceConsumed = ((Number) m.get("spaceConsumed")).longValue();
     final long spaceQuota = ((Number) m.get("spaceQuota")).longValue();
 
-    return new ContentSummary.Builder().length(length).fileCount(fileCount).
+    return new ContentSummary.Builder()
-        directoryCount(directoryCount).quota(quota).spaceConsumed(spaceConsumed).
+        .length(length)
-        spaceQuota(spaceQuota).build();
+        .fileCount(fileCount)
+        .directoryCount(directoryCount)
+        .quota(quota)
+        .spaceConsumed(spaceConsumed)
+        .spaceQuota(spaceQuota).build();
   }
 
   /** Convert a Json map to a MD5MD5CRC32FileChecksum. */
@@ -329,21 +338,22 @@ class JsonUtilClient {
     final int length = ((Number) m.get("length")).intValue();
     final byte[] bytes = StringUtils.hexStringToByte((String) m.get("bytes"));
 
-    final DataInputStream in = new DataInputStream(new ByteArrayInputStream(bytes));
+    final DataInputStream in = new DataInputStream(
+        new ByteArrayInputStream(bytes));
     final DataChecksum.Type crcType =
         MD5MD5CRC32FileChecksum.getCrcTypeFromAlgorithmName(algorithm);
     final MD5MD5CRC32FileChecksum checksum;
 
     // Recreate what DFSClient would have returned.
     switch(crcType) {
-      case CRC32:
+    case CRC32:
-        checksum = new MD5MD5CRC32GzipFileChecksum();
+      checksum = new MD5MD5CRC32GzipFileChecksum();
-        break;
+      break;
-      case CRC32C:
+    case CRC32C:
-        checksum = new MD5MD5CRC32CastagnoliFileChecksum();
+      checksum = new MD5MD5CRC32CastagnoliFileChecksum();
-        break;
+      break;
-      default:
+    default:
-        throw new IOException("Unknown algorithm: " + algorithm);
+      throw new IOException("Unknown algorithm: " + algorithm);
     }
     checksum.readFields(in);
 
@@ -390,14 +400,12 @@ class JsonUtilClient {
     return aclStatusBuilder.build();
   }
 
-  static String getPath(final Map<?, ?> json)
+  static String getPath(final Map<?, ?> json) {
-      throws IOException {
     if (json == null) {
       return null;
     }
 
-    String path = (String) json.get("Path");
+    return (String) json.get("Path");
-    return path;
   }
 
   static byte[] getXAttr(final Map<?, ?> json, final String name)
@@ -446,7 +454,7 @@ class JsonUtilClient {
     ObjectReader reader = new ObjectMapper().reader(List.class);
     final List<Object> xattrs = reader.readValue(namesInJson);
     final List<String> names =
-      Lists.newArrayListWithCapacity(json.keySet().size());
+        Lists.newArrayListWithCapacity(json.keySet().size());
 
     for (Object xattr : xattrs) {
       names.add((String) xattr);
@@ -495,7 +503,8 @@ class JsonUtilClient {
       return null;
     }
 
-    final Map<?, ?> m = (Map<?, ?>)json.get(LocatedBlocks.class.getSimpleName());
+    final Map<?, ?> m = (Map<?, ?>)json.get(
+        LocatedBlocks.class.getSimpleName());
     final long fileLength = ((Number) m.get("fileLength")).longValue();
     final boolean isUnderConstruction = (Boolean)m.get("isUnderConstruction");
     final List<LocatedBlock> locatedBlocks = toLocatedBlockList(

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/URLConnectionFactory.java

@@ -54,38 +54,40 @@ public class URLConnectionFactory {
   /**
    * Timeout for socket connects and reads
    */
-  public final static int DEFAULT_SOCKET_TIMEOUT = 1 * 60 * 1000; // 1 minute
+  public final static int DEFAULT_SOCKET_TIMEOUT = 60 * 1000; // 1 minute
   private final ConnectionConfigurator connConfigurator;
 
-  private static final ConnectionConfigurator DEFAULT_TIMEOUT_CONN_CONFIGURATOR = new ConnectionConfigurator() {
+  private static final ConnectionConfigurator DEFAULT_TIMEOUT_CONN_CONFIGURATOR
-    @Override
+      = new ConnectionConfigurator() {
-    public HttpURLConnection configure(HttpURLConnection conn)
+        @Override
-        throws IOException {
+        public HttpURLConnection configure(HttpURLConnection conn)
-      URLConnectionFactory.setTimeouts(conn, DEFAULT_SOCKET_TIMEOUT);
+            throws IOException {
-      return conn;
+          URLConnectionFactory.setTimeouts(conn, DEFAULT_SOCKET_TIMEOUT);
-    }
+          return conn;
-  };
+        }
+      };
 
   /**
    * The URLConnectionFactory that sets the default timeout and it only trusts
    * Java's SSL certificates.
    */
-  public static final URLConnectionFactory DEFAULT_SYSTEM_CONNECTION_FACTORY = new URLConnectionFactory(
+  public static final URLConnectionFactory DEFAULT_SYSTEM_CONNECTION_FACTORY =
-      DEFAULT_TIMEOUT_CONN_CONFIGURATOR);
+      new URLConnectionFactory(DEFAULT_TIMEOUT_CONN_CONFIGURATOR);
 
   /**
    * Construct a new URLConnectionFactory based on the configuration. It will
    * try to load SSL certificates when it is specified.
    */
-  public static URLConnectionFactory newDefaultURLConnectionFactory(Configuration conf) {
+  public static URLConnectionFactory newDefaultURLConnectionFactory(
+      Configuration conf) {
     ConnectionConfigurator conn = getSSLConnectionConfiguration(conf);
 
     return new URLConnectionFactory(conn);
   }
 
-  private static ConnectionConfigurator
+  private static ConnectionConfigurator getSSLConnectionConfiguration(
-      getSSLConnectionConfiguration(Configuration conf) {
+      Configuration conf) {
-    ConnectionConfigurator conn = null;
+    ConnectionConfigurator conn;
     try {
       conn = newSslConnConfigurator(DEFAULT_SOCKET_TIMEOUT, conf);
     } catch (Exception e) {
@@ -103,9 +105,9 @@ public class URLConnectionFactory {
    * Construct a new URLConnectionFactory that supports OAut-based connections.
    * It will also try to load the SSL configuration when they are specified.
    */
-  public static URLConnectionFactory
+  public static URLConnectionFactory newOAuth2URLConnectionFactory(
-      newOAuth2URLConnectionFactory(Configuration conf) throws IOException {
+      Configuration conf) throws IOException {
-    ConnectionConfigurator conn = null;
+    ConnectionConfigurator conn;
     try {
       ConnectionConfigurator sslConnConfigurator
           = newSslConnConfigurator(DEFAULT_SOCKET_TIMEOUT, conf);
@@ -125,8 +127,9 @@ public class URLConnectionFactory {
   /**
    * Create a new ConnectionConfigurator for SSL connections
    */
-  private static ConnectionConfigurator newSslConnConfigurator(final int timeout,
+  private static ConnectionConfigurator newSslConnConfigurator(
-      Configuration conf) throws IOException, GeneralSecurityException {
+      final int timeout, Configuration conf)
+      throws IOException, GeneralSecurityException {
     final SSLFactory factory;
     final SSLSocketFactory sf;
     final HostnameVerifier hv;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/WebHdfsFileSystem.java

@@ -89,15 +89,20 @@ import com.google.common.collect.Lists;
 
 /** A FileSystem for HDFS over the web. */
 public class WebHdfsFileSystem extends FileSystem
-    implements DelegationTokenRenewer.Renewable, TokenAspect.TokenManagementDelegator {
+    implements DelegationTokenRenewer.Renewable,
+    TokenAspect.TokenManagementDelegator {
   public static final Logger LOG = LoggerFactory
       .getLogger(WebHdfsFileSystem.class);
   /** WebHdfs version. */
   public static final int VERSION = 1;
   /** Http URI: http://namenode:port/{PATH_PREFIX}/path/to/file */
-  public static final String PATH_PREFIX = "/" + WebHdfsConstants.WEBHDFS_SCHEME + "/v" + VERSION;
+  public static final String PATH_PREFIX = "/" + WebHdfsConstants.WEBHDFS_SCHEME
+      + "/v" + VERSION;
 
-  /** Default connection factory may be overridden in tests to use smaller timeout values */
+  /**
+   * Default connection factory may be overridden in tests to use smaller
+   * timeout values
+   */
   protected URLConnectionFactory connectionFactory;
 
   @VisibleForTesting
@@ -141,7 +146,7 @@ public class WebHdfsFileSystem extends FileSystem
 
   @Override
   public synchronized void initialize(URI uri, Configuration conf
-      ) throws IOException {
+  ) throws IOException {
     super.initialize(uri, conf);
     setConf(conf);
     /** set user pattern based on configuration file */
@@ -206,7 +211,7 @@ public class WebHdfsFileSystem extends FileSystem
               failoverSleepMaxMillis);
     }
 
-    this.workingDir = makeQualified(new Path(getHomeDirectoryString(ugi)));
+    this.workingDir = makeQualified(getHomeDirectory());
     this.canRefreshDelegationToken = UserGroupInformation.isSecurityEnabled();
     this.disallowFallbackToInsecureCluster = !conf.getBoolean(
         CommonConfigurationKeys.IPC_CLIENT_FALLBACK_TO_SIMPLE_AUTH_ALLOWED_KEY,
@@ -326,7 +331,7 @@ public class WebHdfsFileSystem extends FileSystem
     String result = absolutePath.toUri().getPath();
     if (!DFSUtilClient.isValidName(result)) {
       throw new IllegalArgumentException("Invalid DFS directory name " +
-                                         result);
+          result);
     }
     workingDir = absolutePath;
   }
@@ -335,14 +340,16 @@ public class WebHdfsFileSystem extends FileSystem
     return f.isAbsolute()? f: new Path(workingDir, f);
   }
 
-  static Map<?, ?> jsonParse(final HttpURLConnection c, final boolean useErrorStream
+  static Map<?, ?> jsonParse(final HttpURLConnection c,
-      ) throws IOException {
+      final boolean useErrorStream) throws IOException {
     if (c.getContentLength() == 0) {
       return null;
     }
-    final InputStream in = useErrorStream? c.getErrorStream(): c.getInputStream();
+    final InputStream in = useErrorStream ?
+        c.getErrorStream() : c.getInputStream();
     if (in == null) {
-      throw new IOException("The " + (useErrorStream? "error": "input") + " stream is null.");
+      throw new IOException("The " + (useErrorStream? "error": "input") +
+          " stream is null.");
     }
     try {
       final String contentType = c.getContentType();
@@ -362,7 +369,8 @@ public class WebHdfsFileSystem extends FileSystem
   }
 
   private static Map<?, ?> validateResponse(final HttpOpParam.Op op,
-      final HttpURLConnection conn, boolean unwrapException) throws IOException {
+      final HttpURLConnection conn, boolean unwrapException)
+      throws IOException {
     final int code = conn.getResponseCode();
     // server is demanding an authentication we don't support
     if (code == HttpURLConnection.HTTP_UNAUTHORIZED) {
@@ -444,7 +452,7 @@ public class WebHdfsFileSystem extends FileSystem
   private URL getNamenodeURL(String path, String query) throws IOException {
     InetSocketAddress nnAddr = getCurrentNNAddr();
     final URL url = new URL(getTransportScheme(), nnAddr.getHostName(),
-          nnAddr.getPort(), path + '?' + query);
+        nnAddr.getPort(), path + '?' + query);
     LOG.trace("url={}", url);
     return url;
   }
@@ -493,7 +501,8 @@ public class WebHdfsFileSystem extends FileSystem
 
     protected final HttpOpParam.Op op;
     private final boolean redirected;
-    protected ExcludeDatanodesParam excludeDatanodes = new ExcludeDatanodesParam("");
+    protected ExcludeDatanodesParam excludeDatanodes =
+        new ExcludeDatanodesParam("");
 
     private boolean checkRetry;
 
@@ -530,7 +539,8 @@ public class WebHdfsFileSystem extends FileSystem
      *
      * Create/Append:
      * Step 1) Submit a Http request with neither auto-redirect nor data.
-     * Step 2) Submit another Http request with the URL from the Location header with data.
+     * Step 2) Submit another Http request with the URL from the Location header
+     * with data.
      *
      * The reason of having two-step create/append is for preventing clients to
      * send out the data before the redirect. This issue is addressed by the
@@ -589,26 +599,25 @@ public class WebHdfsFileSystem extends FileSystem
       conn.setRequestMethod(op.getType().toString());
       conn.setInstanceFollowRedirects(false);
       switch (op.getType()) {
-        // if not sending a message body for a POST or PUT operation, need
+      // if not sending a message body for a POST or PUT operation, need
-        // to ensure the server/proxy knows this
+      // to ensure the server/proxy knows this
-        case POST:
+      case POST:
-        case PUT: {
+      case PUT: {
-          conn.setDoOutput(true);
+        conn.setDoOutput(true);
-          if (!doOutput) {
+        if (!doOutput) {
-            // explicitly setting content-length to 0 won't do spnego!!
+          // explicitly setting content-length to 0 won't do spnego!!
-            // opening and closing the stream will send "Content-Length: 0"
+          // opening and closing the stream will send "Content-Length: 0"
-            conn.getOutputStream().close();
+          conn.getOutputStream().close();
-          } else {
+        } else {
-            conn.setRequestProperty("Content-Type",
+          conn.setRequestProperty("Content-Type",
-                MediaType.APPLICATION_OCTET_STREAM);
+              MediaType.APPLICATION_OCTET_STREAM);
-            conn.setChunkedStreamingMode(32 << 10); //32kB-chunk
+          conn.setChunkedStreamingMode(32 << 10); //32kB-chunk
-          }
-          break;
-        }
-        default: {
-          conn.setDoOutput(doOutput);
-          break;
         }
+        break;
+      }
+      default:
+        conn.setDoOutput(doOutput);
+        break;
       }
       conn.connect();
       return conn;
@@ -658,21 +667,22 @@ public class WebHdfsFileSystem extends FileSystem
     }
 
     private void shouldRetry(final IOException ioe, final int retry
-        ) throws IOException {
+    ) throws IOException {
       InetSocketAddress nnAddr = getCurrentNNAddr();
       if (checkRetry) {
         try {
           final RetryPolicy.RetryAction a = retryPolicy.shouldRetry(
               ioe, retry, 0, true);
 
-          boolean isRetry = a.action == RetryPolicy.RetryAction.RetryDecision.RETRY;
+          boolean isRetry =
+              a.action == RetryPolicy.RetryAction.RetryDecision.RETRY;
           boolean isFailoverAndRetry =
               a.action == RetryPolicy.RetryAction.RetryDecision.FAILOVER_AND_RETRY;
 
           if (isRetry || isFailoverAndRetry) {
             LOG.info("Retrying connect to namenode: {}. Already tried {}"
-                + " time(s); retry policy is {}, delay {}ms.", nnAddr, retry,
+                    + " time(s); retry policy is {}, delay {}ms.",
-                retryPolicy, a.delayMillis);
+                nnAddr, retry, retryPolicy, a.delayMillis);
 
             if (isFailoverAndRetry) {
               resetStateToFailOver();
@@ -795,7 +805,8 @@ public class WebHdfsFileSystem extends FileSystem
   /**
    * Handle create/append output streams
    */
-  class FsPathOutputStreamRunner extends AbstractFsPathRunner<FSDataOutputStream> {
+  class FsPathOutputStreamRunner
+      extends AbstractFsPathRunner<FSDataOutputStream> {
     private final int bufferSize;
 
     FsPathOutputStreamRunner(Op op, Path fspath, int bufferSize,
@@ -846,7 +857,8 @@ public class WebHdfsFileSystem extends FileSystem
       return url;
     }
 
-    protected URLRunner(final HttpOpParam.Op op, final URL url, boolean redirected) {
+    protected URLRunner(final HttpOpParam.Op op, final URL url,
+        boolean redirected) {
       super(op, redirected);
       this.url = url;
     }
@@ -920,7 +932,7 @@ public class WebHdfsFileSystem extends FileSystem
    * Create a symlink pointing to the destination path.
    */
   public void createSymlink(Path destination, Path f, boolean createParent
-      ) throws IOException {
+  ) throws IOException {
     statistics.incrementWriteOps(1);
     final HttpOpParam.Op op = PutOpParam.Op.CREATESYMLINK;
     new FsPathRunner(op, f,
@@ -1029,7 +1041,7 @@ public class WebHdfsFileSystem extends FileSystem
 
   @Override
   public void setOwner(final Path p, final String owner, final String group
-      ) throws IOException {
+  ) throws IOException {
     if (owner == null && group == null) {
       throw new IOException("owner == null && group == null");
     }
@@ -1043,7 +1055,7 @@ public class WebHdfsFileSystem extends FileSystem
 
   @Override
   public void setPermission(final Path p, final FsPermission permission
-      ) throws IOException {
+  ) throws IOException {
     statistics.incrementWriteOps(1);
     final HttpOpParam.Op op = PutOpParam.Op.SETPERMISSION;
     new FsPathRunner(op, p,new PermissionParam(permission)).run();
@@ -1092,14 +1104,13 @@ public class WebHdfsFileSystem extends FileSystem
       throws IOException {
     statistics.incrementWriteOps(1);
     final HttpOpParam.Op op = PutOpParam.Op.CREATESNAPSHOT;
-    Path spath = new FsPathResponseRunner<Path>(op, path,
+    return new FsPathResponseRunner<Path>(op, path,
         new SnapshotNameParam(snapshotName)) {
       @Override
       Path decodeResponse(Map<?,?> json) {
         return new Path((String) json.get(Path.class.getSimpleName()));
       }
     }.run();
-    return spath;
   }
 
   @Override
@@ -1121,7 +1132,7 @@ public class WebHdfsFileSystem extends FileSystem
 
   @Override
   public boolean setReplication(final Path p, final short replication
-     ) throws IOException {
+  ) throws IOException {
     statistics.incrementWriteOps(1);
     final HttpOpParam.Op op = PutOpParam.Op.SETREPLICATION;
     return new FsPathBooleanRunner(op, p,
@@ -1131,7 +1142,7 @@ public class WebHdfsFileSystem extends FileSystem
 
   @Override
   public void setTimes(final Path p, final long mtime, final long atime
-      ) throws IOException {
+  ) throws IOException {
     statistics.incrementWriteOps(1);
     final HttpOpParam.Op op = PutOpParam.Op.SETTIMES;
     new FsPathRunner(op, p,
@@ -1222,7 +1233,7 @@ public class WebHdfsFileSystem extends FileSystem
 
   @Override
   public FSDataInputStream open(final Path f, final int buffersize
-      ) throws IOException {
+  ) throws IOException {
     statistics.incrementReadOps(1);
     final HttpOpParam.Op op = GetOpParam.Op.OPEN;
     // use a runner so the open can recover from an invalid token
@@ -1320,7 +1331,7 @@ public class WebHdfsFileSystem extends FileSystem
     /** Remove offset parameter before returning the resolved url. */
     @Override
     protected URL getResolvedUrl(final HttpURLConnection connection
-        ) throws MalformedURLException {
+    ) throws MalformedURLException {
       return removeOffsetParam(connection.getURL());
     }
   }
@@ -1333,16 +1344,19 @@ public class WebHdfsFileSystem extends FileSystem
     return new FsPathResponseRunner<FileStatus[]>(op, f) {
       @Override
       FileStatus[] decodeResponse(Map<?,?> json) {
-        final Map<?, ?> rootmap = (Map<?, ?>)json.get(FileStatus.class.getSimpleName() + "es");
+        final Map<?, ?> rootmap =
+            (Map<?, ?>)json.get(FileStatus.class.getSimpleName() + "es");
         final List<?> array = JsonUtilClient.getList(rootmap,
-                                                     FileStatus.class.getSimpleName());
+            FileStatus.class.getSimpleName());
 
         //convert FileStatus
+        assert array != null;
         final FileStatus[] statuses = new FileStatus[array.size()];
         int i = 0;
         for (Object object : array) {
           final Map<?, ?> m = (Map<?, ?>) object;
-          statuses[i++] = makeQualified(JsonUtilClient.toFileStatus(m, false), f);
+          statuses[i++] = makeQualified(JsonUtilClient.toFileStatus(m, false),
+              f);
         }
         return statuses;
       }
@@ -1356,12 +1370,12 @@ public class WebHdfsFileSystem extends FileSystem
     Token<DelegationTokenIdentifier> token =
         new FsPathResponseRunner<Token<DelegationTokenIdentifier>>(
             op, null, new RenewerParam(renewer)) {
-      @Override
+          @Override
-      Token<DelegationTokenIdentifier> decodeResponse(Map<?,?> json)
+          Token<DelegationTokenIdentifier> decodeResponse(Map<?,?> json)
-          throws IOException {
+              throws IOException {
-        return JsonUtilClient.toDelegationToken(json);
+            return JsonUtilClient.toDelegationToken(json);
-      }
+          }
-    }.run();
+        }.run();
     if (token != null) {
       token.setService(tokenServiceName);
     } else {
@@ -1387,7 +1401,7 @@ public class WebHdfsFileSystem extends FileSystem
 
   @Override
   public synchronized long renewDelegationToken(final Token<?> token
-      ) throws IOException {
+  ) throws IOException {
     final HttpOpParam.Op op = PutOpParam.Op.RENEWDELEGATIONTOKEN;
     return new FsPathResponseRunner<Long>(op, null,
         new TokenArgumentParam(token.encodeToUrlString())) {
@@ -1400,7 +1414,7 @@ public class WebHdfsFileSystem extends FileSystem
 
   @Override
   public synchronized void cancelDelegationToken(final Token<?> token
-      ) throws IOException {
+  ) throws IOException {
     final HttpOpParam.Op op = PutOpParam.Op.CANCELDELEGATIONTOKEN;
     new FsPathRunner(op, null,
         new TokenArgumentParam(token.encodeToUrlString())
@@ -1453,7 +1467,7 @@ public class WebHdfsFileSystem extends FileSystem
 
   @Override
   public MD5MD5CRC32FileChecksum getFileChecksum(final Path p
-      ) throws IOException {
+  ) throws IOException {
     statistics.incrementReadOps(1);
 
     final HttpOpParam.Op op = GetOpParam.Op.GETFILECHECKSUM;
@@ -1471,11 +1485,11 @@ public class WebHdfsFileSystem extends FileSystem
    * an HA cluster with its logical name, the resolver further resolves the
    * logical name(i.e., the authority in the URL) into real namenode addresses.
    */
-  private InetSocketAddress[] resolveNNAddr() throws IOException {
+  private InetSocketAddress[] resolveNNAddr() {
     Configuration conf = getConf();
     final String scheme = uri.getScheme();
 
-    ArrayList<InetSocketAddress> ret = new ArrayList<InetSocketAddress>();
+    ArrayList<InetSocketAddress> ret = new ArrayList<>();
 
     if (!HAUtilClient.isLogicalUri(conf, uri)) {
       InetSocketAddress addr = NetUtils.createSocketAddr(uri.getAuthority(),

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/resources/ConcatSourcesParam.java

@@ -59,7 +59,6 @@ public class ConcatSourcesParam extends StringParam {
 
   /** @return the absolute path. */
   public final String[] getAbsolutePaths() {
-    final String[] paths = getValue().split(",");
+    return getValue().split(",");
-    return paths;
   }
 }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/resources/CreateFlagParam.java

@@ -30,7 +30,7 @@ public class CreateFlagParam extends EnumSetParam<CreateFlag> {
 
   public static final String DEFAULT = "";
 
-  private static final Domain<CreateFlag> DOMAIN = new Domain<CreateFlag>(
+  private static final Domain<CreateFlag> DOMAIN = new Domain<>(
       NAME, CreateFlag.class);
 
   public CreateFlagParam(final EnumSet<CreateFlag> createFlags) {

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/resources/DeleteOpParam.java

@@ -22,7 +22,7 @@ import java.net.HttpURLConnection;
 /** Http DELETE operation parameter. */
 public class DeleteOpParam extends HttpOpParam<DeleteOpParam.Op> {
   /** Delete operations. */
-  public static enum Op implements HttpOpParam.Op {
+  public enum Op implements HttpOpParam.Op {
     DELETE(HttpURLConnection.HTTP_OK),
     DELETESNAPSHOT(HttpURLConnection.HTTP_OK),
 
@@ -65,7 +65,7 @@ public class DeleteOpParam extends HttpOpParam<DeleteOpParam.Op> {
     }
   }
 
-  private static final Domain<Op> DOMAIN = new Domain<Op>(NAME, Op.class);
+  private static final Domain<Op> DOMAIN = new Domain<>(NAME, Op.class);
 
   /**
    * Constructor.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/resources/EnumParam.java

@@ -20,7 +20,8 @@ package org.apache.hadoop.hdfs.web.resources;
 import java.util.Arrays;
 import org.apache.hadoop.util.StringUtils;
 
-abstract class EnumParam<E extends Enum<E>> extends Param<E, EnumParam.Domain<E>> {
+abstract class EnumParam<E extends Enum<E>>
+    extends Param<E, EnumParam.Domain<E>> {
   EnumParam(final Domain<E> domain, final E value) {
     super(domain, value);
   }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/resources/EnumSetParam.java

@@ -22,7 +22,8 @@ import java.util.EnumSet;
 import java.util.Iterator;
 import org.apache.hadoop.util.StringUtils;
 
-abstract class EnumSetParam<E extends Enum<E>> extends Param<EnumSet<E>, EnumSetParam.Domain<E>> {
+abstract class EnumSetParam<E extends Enum<E>>
+    extends Param<EnumSet<E>, EnumSetParam.Domain<E>> {
   /** Convert an EnumSet to a string of comma separated values. */
   static <E extends Enum<E>> String toString(EnumSet<E> set) {
     if (set == null || set.isEmpty()) {

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/resources/GetOpParam.java

@@ -22,7 +22,7 @@ import java.net.HttpURLConnection;
 /** Http GET operation parameter. */
 public class GetOpParam extends HttpOpParam<GetOpParam.Op> {
   /** Get operations. */
-  public static enum Op implements HttpOpParam.Op {
+  public enum Op implements HttpOpParam.Op {
     OPEN(true, HttpURLConnection.HTTP_OK),
 
     GETFILESTATUS(false, HttpURLConnection.HTTP_OK),
@@ -52,7 +52,7 @@ public class GetOpParam extends HttpOpParam<GetOpParam.Op> {
     }
 
     Op(final boolean redirect, final int expectedHttpResponseCode,
-       final boolean requireAuth) {
+        final boolean requireAuth) {
       this.redirect = redirect;
       this.expectedHttpResponseCode = expectedHttpResponseCode;
       this.requireAuth = requireAuth;
@@ -89,7 +89,7 @@ public class GetOpParam extends HttpOpParam<GetOpParam.Op> {
     }
   }
 
-  private static final Domain<Op> DOMAIN = new Domain<Op>(NAME, Op.class);
+  private static final Domain<Op> DOMAIN = new Domain<>(NAME, Op.class);
 
   /**
    * Constructor.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/resources/HttpOpParam.java

@@ -34,29 +34,29 @@ public abstract class HttpOpParam<E extends Enum<E> & HttpOpParam.Op>
   public static final String DEFAULT = NULL;
 
   /** Http operation types */
-  public static enum Type {
+  public enum Type {
-    GET, PUT, POST, DELETE;
+    GET, PUT, POST, DELETE
   }
 
   /** Http operation interface. */
-  public static interface Op {
+  public interface Op {
     /** @return the Http operation type. */
-    public Type getType();
+    Type getType();
 
     /** @return true if the operation cannot use a token */
-    public boolean getRequireAuth();
+    boolean getRequireAuth();
 
     /** @return true if the operation will do output. */
-    public boolean getDoOutput();
+    boolean getDoOutput();
 
     /** @return true if the operation will be redirected. */
-    public boolean getRedirect();
+    boolean getRedirect();
 
     /** @return true the expected http response code. */
-    public int getExpectedHttpResponseCode();
+    int getExpectedHttpResponseCode();
 
     /** @return a URI query string. */
-    public String toQueryString();
+    String toQueryString();
   }
 
   /** Expects HTTP response 307 "Temporary Redirect". */

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/resources/LongParam.java

@@ -19,7 +19,8 @@ package org.apache.hadoop.hdfs.web.resources;
 
 /** Long parameter. */
 abstract class LongParam extends Param<Long, LongParam.Domain> {
-  LongParam(final Domain domain, final Long value, final Long min, final Long max) {
+  LongParam(final Domain domain, final Long value, final Long min,
+            final Long max) {
     super(domain, value);
     checkRange(min, max);
   }

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/resources/Param.java

@@ -47,16 +47,16 @@ public abstract class Param<T, D extends Param.Domain<T>> {
     try {
       for(Param<?, ?> p : parameters) {
         if (p.getValue() != null) {
-          b.append(separator).append(
+          b.append(separator)
-              URLEncoder.encode(p.getName(), "UTF-8")
+              .append(URLEncoder.encode(p.getName(), "UTF-8"))
-              + "="
+              .append("=")
-              + URLEncoder.encode(p.getValueString(), "UTF-8"));
+              .append(URLEncoder.encode(p.getValueString(), "UTF-8"));
         }
       }
-  } catch (UnsupportedEncodingException e) {
+    } catch (UnsupportedEncodingException e) {
-    // Sane systems know about UTF-8, so this should never happen.
+      // Sane systems know about UTF-8, so this should never happen.
-    throw new RuntimeException(e);
+      throw new RuntimeException(e);
-  }
+    }
     return b.toString();
   }
 

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/resources/PostOpParam.java

@@ -22,7 +22,7 @@ import java.net.HttpURLConnection;
 /** Http POST operation parameter. */
 public class PostOpParam extends HttpOpParam<PostOpParam.Op> {
   /** Post operations. */
-  public static enum Op implements HttpOpParam.Op {
+  public enum Op implements HttpOpParam.Op {
     APPEND(true, HttpURLConnection.HTTP_OK),
 
     CONCAT(false, HttpURLConnection.HTTP_OK),
@@ -71,7 +71,7 @@ public class PostOpParam extends HttpOpParam<PostOpParam.Op> {
     }
   }
 
-  private static final Domain<Op> DOMAIN = new Domain<PostOpParam.Op>(NAME, Op.class);
+  private static final Domain<Op> DOMAIN = new Domain<>(NAME, Op.class);
 
   /**
    * Constructor.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/resources/PutOpParam.java

@@ -22,7 +22,7 @@ import java.net.HttpURLConnection;
 /** Http POST operation parameter. */
 public class PutOpParam extends HttpOpParam<PutOpParam.Op> {
   /** Put operations. */
-  public static enum Op implements HttpOpParam.Op {
+  public enum Op implements HttpOpParam.Op {
     CREATE(true, HttpURLConnection.HTTP_CREATED),
 
     MKDIRS(false, HttpURLConnection.HTTP_OK),
@@ -60,7 +60,7 @@ public class PutOpParam extends HttpOpParam<PutOpParam.Op> {
     }
 
     Op(final boolean doOutputAndRedirect, final int expectedHttpResponseCode,
-       final boolean requireAuth) {
+        final boolean requireAuth) {
       this.doOutputAndRedirect = doOutputAndRedirect;
       this.expectedHttpResponseCode = expectedHttpResponseCode;
       this.requireAuth = requireAuth;
@@ -97,7 +97,7 @@ public class PutOpParam extends HttpOpParam<PutOpParam.Op> {
     }
   }
 
-  private static final Domain<Op> DOMAIN = new Domain<Op>(NAME, Op.class);
+  private static final Domain<Op> DOMAIN = new Domain<>(NAME, Op.class);
 
   /**
    * Constructor.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/resources/RenameOptionSetParam.java

@@ -26,7 +26,7 @@ public class RenameOptionSetParam extends EnumSetParam<Options.Rename> {
   /** Default parameter value. */
   public static final String DEFAULT = "";
 
-  private static final Domain<Options.Rename> DOMAIN = new Domain<Options.Rename>(
+  private static final Domain<Options.Rename> DOMAIN = new Domain<>(
       NAME, Options.Rename.class);
 
   /**