HBASE-20478 Update checkstyle to v8.2

Cannot go to latest (8.9) yet due to
  https://github.com/checkstyle/checkstyle/issues/5279

* move hbaseanti import checks to checkstyle
* implment a few missing equals checks, and ignore one
* fix lots of javadoc errors

Signed-off-by: Sean Busbey <busbey@apache.org>

dev-support/hbase-personality.sh

@@ -631,24 +631,6 @@ function hbaseanti_patchfile
     ((result=result+1))
   fi
 
-  warnings=$(${GREP} -c 'import org.apache.hadoop.classification' "${patchfile}")
-  if [[ ${warnings} -gt 0 ]]; then
-    add_vote_table -1 hbaseanti "" "The patch appears use Hadoop classification instead of HBase."
-    ((result=result+1))
-  fi
-
-  warnings=$(${GREP} -c 'import org.codehaus.jackson' "${patchfile}")
-  if [[ ${warnings} -gt 0 ]]; then
-    add_vote_table -1 hbaseanti "" "The patch appears use Jackson 1 classes/annotations."
-    ((result=result+1))
-  fi
-
-  warnings=$(${GREP} -cE 'org.apache.commons.logging.Log(Factory|;)' "${patchfile}")
-  if [[ ${warnings} -gt 0 ]]; then
-    add_vote_table -1 hbaseanti "" "The patch appears to use commons-logging instead of slf4j."
-    ((result=result+1))
-  fi
-
   if [[ ${result} -gt 0 ]]; then
     return 1
   fi

hbase-backup/src/main/java/org/apache/hadoop/hbase/backup/impl/RestoreTablesClient.java

@@ -77,7 +77,7 @@ public class RestoreTablesClient {
   /**
    * Validate target tables.
    *
-   * @param tTableArray: target tables
+   * @param tTableArray target tables
    * @param isOverwrite overwrite existing table
    * @throws IOException exception
    */
@@ -123,10 +123,10 @@ public class RestoreTablesClient {
   /**
    * Restore operation handle each backupImage in array.
    *
-   * @param images: array BackupImage
+   * @param images array BackupImage
-   * @param sTable: table to be restored
+   * @param sTable table to be restored
-   * @param tTable: table to be restored to
+   * @param tTable table to be restored to
-   * @param truncateIfExists: truncate table
+   * @param truncateIfExists truncate table
    * @throws IOException exception
    */
 

hbase-checkstyle/src/main/resources/hbase/checkstyle-suppressions.xml

@@ -37,4 +37,5 @@
   <suppress checks="VisibilityModifier" files=".*/src/test/.*\.java"/>
   <suppress checks="InterfaceIsTypeCheck" files=".*/src/main/.*\.java"/>
   <suppress checks="EmptyBlockCheck" files="TBoundedThreadPoolServer.java"/>
+  <suppress checks="EqualsHashCode" files="StartcodeAgnosticServerName.java"/>
 </suppressions>

hbase-checkstyle/src/main/resources/hbase/checkstyle.xml

@@ -51,6 +51,7 @@
     <module name="VisibilityModifier">
       <property name="packageAllowed" value="true"/>
       <property name="protectedAllowed" value="true"/>
+      <property name="allowPublicImmutableFields" value="true"/>
     </module>
 
     <!-- Coding Checks
@@ -85,7 +86,12 @@
           org.apache.commons.collections4,
           org.apache.commons.lang,
           org.apache.curator.shaded,
-          org.apache.htrace.shaded"/>
+          org.apache.hadoop.classification,
+          org.apache.htrace.shaded,
+          org.codehaus.jackson"/>
+      <property name="illegalClasses" value="
+          org.apache.commons.logging.Log,
+          org.apache.commons.logging.LogFactory"/>
     </module>
     <!-- Javadoc Checks
     http://checkstyle.sourceforge.net/config_javadoc.html -->

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ClusterConnection.java

@@ -232,7 +232,7 @@ public interface ClusterConnection extends Connection {
 
   /**
    * Establishes a connection to the region server at the specified address.
-   * @param serverName
+   * @param serverName the region server to connect to
    * @return proxy for HRegionServer
    * @throws IOException if a remote or network exception occurs
    */
@@ -242,7 +242,7 @@ public interface ClusterConnection extends Connection {
    * Establishes a connection to the region server at the specified address, and returns
    * a region client protocol.
    *
-   * @param serverName
+   * @param serverName the region server to connect to
    * @return ClientProtocol proxy for RegionServer
    * @throws IOException if a remote or network exception occurs
    *

hbase-client/src/main/java/org/apache/hadoop/hbase/client/replication/TableCFs.java

@@ -26,7 +26,7 @@ import org.apache.yetus.audience.InterfaceAudience;
 
 /**
  * Used by {@link org.apache.hadoop.hbase.client.Admin#listReplicatedTableCFs()}.
- * The cfs is a map of <ColumnFamily, ReplicationScope>.
+ * The cfs is a map of &lt;ColumnFamily, ReplicationScope>.
  */
 @InterfaceAudience.Public
 public class TableCFs {

hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/ProtobufUtil.java

@@ -1559,7 +1559,7 @@ public final class ProtobufUtil {
 
 
   /**
-   * @see {@link #buildGetServerInfoRequest()}
+   * @see #buildGetServerInfoRequest()
    */
   private static GetServerInfoRequest GET_SERVER_INFO_REQUEST =
     GetServerInfoRequest.newBuilder().build();

hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/QuotaTableUtil.java

@@ -86,7 +86,7 @@ import org.apache.hadoop.hbase.util.Bytes;
  *   <tr><td>u.&lt;user&gt;</td><td>q:s</td><td>&lt;global-quotas&gt;</td></tr>
  *   <tr><td>u.&lt;user&gt;</td><td>q:s.&lt;table&gt;</td><td>&lt;table-quotas&gt;</td></tr>
  *   <tr><td>u.&lt;user&gt;</td><td>q:s.&lt;ns&gt;</td><td>&lt;namespace-quotas&gt;</td></tr>
- * </table
+ * </table>
  */
 @InterfaceAudience.Private
 @InterfaceStability.Evolving

hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/RequestConverter.java

@@ -1026,7 +1026,7 @@ public final class RequestConverter {
   }
 
   /**
-   * @see {@link #buildRollWALWriterRequest()}
+   * @see #buildRollWALWriterRequest()
    */
   private static RollWALWriterRequest ROLL_WAL_WRITER_REQUEST = RollWALWriterRequest.newBuilder()
       .build();
@@ -1040,7 +1040,7 @@ public final class RequestConverter {
   }
 
   /**
-   * @see {@link #buildGetServerInfoRequest()}
+   * @see #buildGetServerInfoRequest()
    */
   private static GetServerInfoRequest GET_SERVER_INFO_REQUEST = GetServerInfoRequest.newBuilder()
       .build();
@@ -1522,7 +1522,7 @@ public final class RequestConverter {
   }
 
   /**
-   * @see {@link #buildCatalogScanRequest}
+   * @see #buildCatalogScanRequest
    */
   private static final RunCatalogScanRequest CATALOG_SCAN_REQUEST =
     RunCatalogScanRequest.newBuilder().build();
@@ -1544,7 +1544,7 @@ public final class RequestConverter {
   }
 
   /**
-   * @see {@link #buildIsCatalogJanitorEnabledRequest()}
+   * @see #buildIsCatalogJanitorEnabledRequest()
    */
   private static final IsCatalogJanitorEnabledRequest IS_CATALOG_JANITOR_ENABLED_REQUEST =
     IsCatalogJanitorEnabledRequest.newBuilder().build();
@@ -1558,7 +1558,7 @@ public final class RequestConverter {
   }
 
   /**
-   * @see {@link #buildCleanerChoreRequest}
+   * @see #buildRunCleanerChoreRequest()
    */
   private static final RunCleanerChoreRequest CLEANER_CHORE_REQUEST =
     RunCleanerChoreRequest.newBuilder().build();
@@ -1580,7 +1580,7 @@ public final class RequestConverter {
   }
 
   /**
-   * @see {@link #buildIsCleanerChoreEnabledRequest()}
+   * @see #buildIsCleanerChoreEnabledRequest()
    */
   private static final IsCleanerChoreEnabledRequest IS_CLEANER_CHORE_ENABLED_REQUEST =
     IsCleanerChoreEnabledRequest.newBuilder().build();

hbase-common/src/main/java/org/apache/hadoop/hbase/net/Address.java

@@ -26,7 +26,7 @@ import org.apache.hbase.thirdparty.com.google.common.net.HostAndPort;
  * An immutable type to hold a hostname and port combo, like an Endpoint
  * or java.net.InetSocketAddress (but without danger of our calling
  * resolve -- we do NOT want a resolve happening every time we want
- * to hold a hostname and port combo). This class is also <<Comparable>>.
+ * to hold a hostname and port combo). This class is also {@link Comparable}
  * <p>In implementation this class is a facade over Guava's {@link HostAndPort}.
  * We cannot have Guava classes in our API hence this Type.
  */

hbase-common/src/main/java/org/apache/hadoop/hbase/util/AbstractByteRange.java

@@ -315,6 +315,20 @@ public abstract class AbstractByteRange implements ByteRange {
     hash = UNSET_HASH_VALUE;
   }
 
+  @Override
+  public boolean equals(Object obj) {
+    if (this == obj) {
+      return true;
+    }
+    if (obj == null) {
+      return false;
+    }
+    if (!(obj instanceof ByteRange)) {
+      return false;
+    }
+    return compareTo((ByteRange) obj) == 0;
+  }
+
   /**
    * Bitwise comparison of each byte in the array. Unsigned comparison, not
    * paying attention to java's signed bytes.

hbase-common/src/main/java/org/apache/hadoop/hbase/util/JRubyFormat.java

@@ -30,12 +30,13 @@ import org.apache.hbase.thirdparty.com.google.common.escape.Escapers;
 /**
  * Utility class for converting objects to JRuby.
  *
- * It handles null, Boolean, Number, String, byte[], List<Object>, Map<String, Object> structures.
+ * It handles null, Boolean, Number, String, byte[], List&lt;Object>, Map&lt;String, Object>
+ *   structures.
  *
  * <p>
  * E.g.
  * <pre>
- * Map<String, Object> map = new LinkedHashMap<>();
+ * Map&lt;String, Object> map = new LinkedHashMap&lt;>();
  * map.put("null", null);
  * map.put("boolean", true);
  * map.put("number", 1);
@@ -48,7 +49,8 @@ import org.apache.hbase.thirdparty.com.google.common.escape.Escapers;
  * <p>
  * Calling {@link #print(Object)} method will result:
  * <pre>
- * { null => '', boolean => 'true', number => '1', string => 'str', binary => '010203', list => [ '1', '2', 'true' ] }
+ * { null => '', boolean => 'true', number => '1', string => 'str',
+ *   binary => '010203', list => [ '1', '2', 'true' ] }
  * </pre>
  * </p>
  */

hbase-common/src/main/java/org/apache/hadoop/hbase/util/OrderedBytes.java

@@ -339,7 +339,7 @@ public class OrderedBytes {
 
   /**
    * Perform unsigned comparison between two long values. Conforms to the same interface as
-   * {@link org.apache.hadoop.hbase.CellComparator#COMPARATOR#compare(Object, Object)}.
+   * {@link org.apache.hadoop.hbase.CellComparator}.
    */
   private static int unsignedCmp(long x1, long x2) {
     int cmp;

hbase-common/src/test/java/org/apache/hadoop/hbase/Waiter.java

@@ -83,7 +83,7 @@ public final class Waiter {
   /**
    * A predicate 'closure' used by the {@link Waiter#waitFor(Configuration, long, Predicate)} and
    * {@link Waiter#waitFor(Configuration, long, Predicate)} and
-   * {@link Waiter#waitFor(Configuration, long, long, boolean, Predicate) methods.
+   * {@link Waiter#waitFor(Configuration, long, long, boolean, Predicate)} methods.
    */
   @InterfaceAudience.Private
   public interface Predicate<E extends Exception> {

hbase-endpoint/src/main/java/org/apache/hadoop/hbase/security/access/SecureBulkLoadEndpoint.java

@@ -95,6 +95,9 @@ public class SecureBulkLoadEndpoint extends SecureBulkLoadService implements Reg
     done.run(null);
   }
 
+  /**
+   *  Convert from CPEP protobuf 2.5 to internal protobuf 3.3.
+   */
   org.apache.hadoop.hbase.shaded.protobuf.generated.ClientProtos.PrepareBulkLoadRequest
     convert(PrepareBulkLoadRequest request)
   throws org.apache.hbase.thirdparty.com.google.protobuf.InvalidProtocolBufferException {
@@ -121,8 +124,7 @@ public class SecureBulkLoadEndpoint extends SecureBulkLoadService implements Reg
   }
 
   /**
-   * Convert from CPEP protobuf 2.5 to internal protobuf 3.3.
+   *  Convert from CPEP protobuf 2.5 to internal protobuf 3.3.
-   * @throws org.apache.hbase.thirdparty.com.google.protobuf.InvalidProtocolBufferException
    */
   org.apache.hadoop.hbase.shaded.protobuf.generated.ClientProtos.CleanupBulkLoadRequest
   convert(CleanupBulkLoadRequest request)
@@ -153,6 +155,9 @@ public class SecureBulkLoadEndpoint extends SecureBulkLoadService implements Reg
     done.run(SecureBulkLoadHFilesResponse.newBuilder().setLoaded(loaded).build());
   }
 
+  /**
+   *  Convert from CPEP protobuf 2.5 to internal protobuf 3.3.
+   */
   org.apache.hadoop.hbase.shaded.protobuf.generated.ClientProtos.BulkLoadHFileRequest
   convert(BulkLoadHFileRequest request)
       throws org.apache.hbase.thirdparty.com.google.protobuf.InvalidProtocolBufferException {

hbase-http/src/test/java/org/apache/hadoop/hbase/http/TestHttpServer.java

@@ -322,10 +322,10 @@ public class TestHttpServer extends HttpServerFunctionalTest {
    * will be accessed as the passed user, by sending user.name request
    * parameter.
    *
-   * @param urlstring
+   * @param urlstring The url to access
-   * @param userName
+   * @param userName The user to perform access as
-   * @return
+   * @return The HTTP response code
-   * @throws IOException
+   * @throws IOException if there is a problem communicating with the server
    */
   static int getHttpStatusCode(String urlstring, String userName)
       throws IOException {

hbase-it/src/test/java/org/apache/hadoop/hbase/IntegrationTestBase.java

@@ -38,10 +38,10 @@ import org.apache.hbase.thirdparty.org.apache.commons.cli.CommandLine;
 
 /**
  * Base class for HBase integration tests that want to use the Chaos Monkey.
- * Usage: bin/hbase <sub_class_of_IntegrationTestBase> <options>
+ * Usage: bin/hbase &lt;sub_class_of_IntegrationTestBase> &lt;options>
  * Options: -h,--help Show usage
- *          -m,--monkey <arg> Which chaos monkey to run
+ *          -m,--monkey &lt;arg> Which chaos monkey to run
- *          -monkeyProps <arg> The properties file for specifying chaos monkey properties.
+ *          -monkeyProps &lt;arg> The properties file for specifying chaos monkey properties.
  *          -ncc Option to not clean up the cluster at the end.
  */
 public abstract class IntegrationTestBase extends AbstractHBaseTool {

hbase-it/src/test/java/org/apache/hadoop/hbase/IntegrationTestRegionReplicaReplication.java

@@ -50,7 +50,7 @@ import org.apache.hbase.thirdparty.com.google.common.collect.Lists;
  * with the replication of the edits before read_delay_ms to the given region replica id so that
  * the read and verify will not fail.
  *
- * The job will run for <b>at least<b> given runtime (default 10min) by running a concurrent
+ * The job will run for <b>at least</b> given runtime (default 10min) by running a concurrent
  * writer and reader workload followed by a concurrent updater and reader workload for
  * num_keys_per_server.
  * <p>

hbase-mapreduce/src/test/java/org/apache/hadoop/hbase/mapred/TestTableInputFormat.java

@@ -107,8 +107,8 @@ public class TestTableInputFormat {
   /**
    * Setup a table with two rows and values.
    *
-   * @param tableName
+   * @param tableName the name of the table to create
-   * @return
+   * @return A Table instance for the created table.
    * @throws IOException
    */
   public static Table createTable(byte[] tableName) throws IOException {
@@ -119,7 +119,7 @@ public class TestTableInputFormat {
    * Setup a table with two rows and values per column family.
    *
    * @param tableName
-   * @return
+   * @return A Table instance for the created table.
    * @throws IOException
    */
   public static Table createTable(byte[] tableName, byte[][] families) throws IOException {

hbase-mapreduce/src/test/java/org/apache/hadoop/hbase/mapreduce/TestImportExport.java

@@ -537,9 +537,9 @@ public class TestImportExport {
   }
 
   /**
-   * Count the number of keyvalues in the specified table for the given timerange
+   * Count the number of keyvalues in the specified table with the given filter
-   * @param table
+   * @param table the table to scan
-   * @return
+   * @return the number of keyvalues found
    * @throws IOException
    */
   private int getCount(Table table, Filter filter) throws IOException {

hbase-mapreduce/src/test/java/org/apache/hadoop/hbase/mapreduce/TestTableInputFormat.java

@@ -105,7 +105,7 @@ public class TestTableInputFormat {
    * Setup a table with two rows and values.
    *
    * @param tableName
-   * @return
+   * @return A Table instance for the created table.
    * @throws IOException
    */
   public static Table createTable(byte[] tableName) throws IOException {
@@ -116,7 +116,7 @@ public class TestTableInputFormat {
    * Setup a table with two rows and values per column family.
    *
    * @param tableName
-   * @return
+   * @return A Table instance for the created table.
    * @throws IOException
    */
   public static Table createTable(byte[] tableName, byte[][] families) throws IOException {

hbase-mapreduce/src/test/java/org/apache/hadoop/hbase/util/LoadTestTool.java

@@ -820,10 +820,10 @@ public class LoadTestTool extends AbstractHBaseTool {
   /**
    * When NUM_TABLES is specified, the function starts multiple worker threads
    * which individually start a LoadTestTool instance to load a table. Each
-   * table name is in format <tn>_<index>. For example, "-tn test -num_tables 2"
+   * table name is in format &lt;tn>_&lt;index>. For example, "-tn test -num_tables 2"
    * , table names will be "test_1", "test_2"
    *
-   * @throws IOException
+   * @throws IOException if one of the load tasks is unable to complete
    */
   private int parallelLoadTables()
       throws IOException {

hbase-server/src/main/java/org/apache/hadoop/hbase/favored/StartcodeAgnosticServerName.java

@@ -63,4 +63,8 @@ class StartcodeAgnosticServerName extends ServerName {
   public int hashCode() {
     return getHostAndPort().hashCode();
   }
+
+  // Do not need @Override #equals() because super.equals() delegates to compareTo(), which ends
+  // up doing the right thing. We have a test for it, so the checkstyle warning here would be a
+  // false positive.
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFileBlockIndex.java

@@ -1481,7 +1481,7 @@ public class HFileBlockIndex {
      * The same as {@link #add(byte[], long, int, long)} but does not take the
      * key/value into account. Used for single-level indexes.
      *
-     * @see {@link #add(byte[], long, int, long)}
+     * @see #add(byte[], long, int, long)
      */
     public void add(byte[] firstKey, long blockOffset, int onDiskDataSize) {
       add(firstKey, blockOffset, onDiskDataSize, -1);

hbase-server/src/main/java/org/apache/hadoop/hbase/ipc/RpcServer.java

@@ -585,7 +585,7 @@ public abstract class RpcServer implements RpcServerInterface,
   }
 
   /**
-   * Helper for {@link #channelRead(java.nio.channels.ReadableByteChannel, java.nio.ByteBuffer).
+   * Helper for {@link #channelRead(java.nio.channels.ReadableByteChannel, java.nio.ByteBuffer)}.
    * Only one of readCh or writeCh should be non-null.
    *
    * @param readCh read channel

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StoreFlushContext.java

@@ -57,7 +57,7 @@ interface StoreFlushContext {
    *
    * A very short operation
    *
-   * @return
+   * @return whether compaction is required
    * @throws IOException
    */
   boolean commit(MonitoredTask status) throws IOException;

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/querymatcher/ColumnTracker.java

@@ -60,7 +60,7 @@ public interface ColumnTracker extends ShipperListener {
    * method based on the return type (INCLUDE) of this method. The values that can be returned by
    * this method are {@link MatchCode#INCLUDE}, {@link MatchCode#SEEK_NEXT_COL} and
    * {@link MatchCode#SEEK_NEXT_ROW}.
-   * @param cell
+   * @param cell a cell with the column to match against
    * @param type The type of the Cell
    * @return The match code instance.
    * @throws IOException in case there is an internal consistency problem caused by a data
@@ -77,7 +77,7 @@ public interface ColumnTracker extends ShipperListener {
    * Implementations which include all the columns could just return {@link MatchCode#INCLUDE} in
    * the {@link #checkColumn(Cell, byte)} method and perform all the operations in this
    * checkVersions method.
-   * @param cell
+   * @param cell a cell with the column to match against
    * @param timestamp The timestamp of the cell.
    * @param type the type of the key value (Put/Delete)
    * @param ignoreCount indicates if the KV needs to be excluded while counting (used during

hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/AccessControlFilter.java

@@ -165,7 +165,7 @@ class AccessControlFilter extends FilterBase {
    * @param pbBytes A pb serialized {@link AccessControlFilter} instance
    * @return An instance of {@link AccessControlFilter} made from <code>bytes</code>
    * @throws org.apache.hadoop.hbase.exceptions.DeserializationException
-   * @see {@link #toByteArray()}
+   * @see #toByteArray()
    */
   public static AccessControlFilter parseFrom(final byte [] pbBytes)
   throws DeserializationException {

hbase-server/src/test/java/org/apache/hadoop/hbase/HBaseTestingUtility.java

@@ -590,7 +590,7 @@ public class HBaseTestingUtility extends HBaseZKTestingUtility {
    * Start a minidfscluster.
    * @param servers How many DNs to start.
    * @throws Exception
-   * @see {@link #shutdownMiniDFSCluster()}
+   * @see #shutdownMiniDFSCluster()
    * @return The mini dfs cluster created.
    */
   public MiniDFSCluster startMiniDFSCluster(int servers) throws Exception {
@@ -605,7 +605,7 @@ public class HBaseTestingUtility extends HBaseZKTestingUtility {
    * datanodes will have the same host name.
    * @param hosts hostnames DNs to run on.
    * @throws Exception
-   * @see {@link #shutdownMiniDFSCluster()}
+   * @see #shutdownMiniDFSCluster()
    * @return The mini dfs cluster created.
    */
   public MiniDFSCluster startMiniDFSCluster(final String hosts[])
@@ -623,7 +623,7 @@ public class HBaseTestingUtility extends HBaseZKTestingUtility {
    * @param servers How many DNs to start.
    * @param hosts hostnames DNs to run on.
    * @throws Exception
-   * @see {@link #shutdownMiniDFSCluster()}
+   * @see #shutdownMiniDFSCluster()
    * @return The mini dfs cluster created.
    */
   public MiniDFSCluster startMiniDFSCluster(int servers, final String hosts[])
@@ -767,7 +767,7 @@ public class HBaseTestingUtility extends HBaseZKTestingUtility {
    * Start up a minicluster of hbase, dfs, and zookeeper.
    * @throws Exception
    * @return Mini hbase cluster instance created.
-   * @see {@link #shutdownMiniDFSCluster()}
+   * @see #shutdownMiniDFSCluster()
    */
   public MiniHBaseCluster startMiniCluster() throws Exception {
     return startMiniCluster(1, 1);
@@ -777,7 +777,7 @@ public class HBaseTestingUtility extends HBaseZKTestingUtility {
    * Start up a minicluster of hbase, dfs, and zookeeper where WAL's walDir is created separately.
    * @throws Exception
    * @return Mini hbase cluster instance created.
-   * @see {@link #shutdownMiniDFSCluster()}
+   * @see #shutdownMiniDFSCluster()
    */
   public MiniHBaseCluster startMiniCluster(boolean withWALDir) throws Exception {
     return startMiniCluster(1, 1, 1, null, null, null, false, withWALDir);
@@ -789,7 +789,7 @@ public class HBaseTestingUtility extends HBaseZKTestingUtility {
    * (will overwrite if dir already exists)
    * @throws Exception
    * @return Mini hbase cluster instance created.
-   * @see {@link #shutdownMiniDFSCluster()}
+   * @see #shutdownMiniDFSCluster()
    */
   public MiniHBaseCluster startMiniCluster(final int numSlaves, boolean create)
   throws Exception {
@@ -806,7 +806,7 @@ public class HBaseTestingUtility extends HBaseZKTestingUtility {
    * hbase.regionserver.info.port is -1 (i.e. no ui per regionserver) otherwise
    * bind errors.
    * @throws Exception
-   * @see {@link #shutdownMiniCluster()}
+   * @see #shutdownMiniCluster()
    * @return Mini hbase cluster instance created.
    */
   public MiniHBaseCluster startMiniCluster(final int numSlaves)
@@ -823,7 +823,7 @@ public class HBaseTestingUtility extends HBaseZKTestingUtility {
    * Start minicluster. Whether to create a new root or data dir path even if such a path
    * has been created earlier is decided based on flag <code>create</code>
    * @throws Exception
-   * @see {@link #shutdownMiniCluster()}
+   * @see #shutdownMiniCluster()
    * @return Mini hbase cluster instance created.
    */
   public MiniHBaseCluster startMiniCluster(final int numMasters,
@@ -835,7 +835,7 @@ public class HBaseTestingUtility extends HBaseZKTestingUtility {
   /**
    * start minicluster
    * @throws Exception
-   * @see {@link #shutdownMiniCluster()}
+   * @see #shutdownMiniCluster()
    * @return Mini hbase cluster instance created.
    */
   public MiniHBaseCluster startMiniCluster(final int numMasters,
@@ -872,7 +872,7 @@ public class HBaseTestingUtility extends HBaseZKTestingUtility {
    * If you start MiniDFSCluster without host names,
    * all instances of the datanodes will have the same host name.
    * @throws Exception
-   * @see {@link #shutdownMiniCluster()}
+   * @see #shutdownMiniCluster()
    * @return Mini hbase cluster instance created.
    */
   public MiniHBaseCluster startMiniCluster(final int numMasters,
@@ -914,7 +914,7 @@ public class HBaseTestingUtility extends HBaseZKTestingUtility {
    * @param regionserverClass The class to use as HRegionServer, or null for
    * default
    * @throws Exception
-   * @see {@link #shutdownMiniCluster()}
+   * @see #shutdownMiniCluster()
    * @return Mini hbase cluster instance created.
    */
   public MiniHBaseCluster startMiniCluster(final int numMasters,
@@ -1003,7 +1003,7 @@ public class HBaseTestingUtility extends HBaseZKTestingUtility {
    * @return Reference to the hbase mini hbase cluster.
    * @throws IOException
    * @throws InterruptedException
-   * @see {@link #startMiniCluster()}
+   * @see #startMiniCluster()
    */
   public MiniHBaseCluster startMiniHBaseCluster(final int numMasters,
         final int numSlaves, List<Integer> rsPorts, Class<? extends HMaster> masterClass,
@@ -1088,7 +1088,7 @@ public class HBaseTestingUtility extends HBaseZKTestingUtility {
   /**
    * Stops mini hbase, zk, and hdfs clusters.
    * @throws IOException
-   * @see {@link #startMiniCluster(int)}
+   * @see #startMiniCluster(int)
    */
   public void shutdownMiniCluster() throws Exception {
     LOG.info("Shutting down minicluster");
@@ -1746,10 +1746,10 @@ public class HBaseTestingUtility extends HBaseZKTestingUtility {
 
   /**
    * Create an HRegion that writes to the local tmp dirs
-   * @param desc
+   * @param desc a table descriptor indicating which table the region belongs to
-   * @param startKey
+   * @param startKey the start boundary of the region
-   * @param endKey
+   * @param endKey the end boundary of the region
-   * @return
+   * @return a region that writes to local dir for testing
    * @throws IOException
    */
   public HRegion createLocalHRegion(TableDescriptor desc, byte [] startKey,

hbase-server/src/test/java/org/apache/hadoop/hbase/MultithreadedTestUtil.java

@@ -163,26 +163,25 @@ public abstract class MultithreadedTestUtil {
    * Verify that no assertions have failed inside a future.
    * Used for unit tests that spawn threads. E.g.,
    * <p>
-   * <code>
+   * <pre>
-   *   List<Future<Void>> results = Lists.newArrayList();
+   *   List&lt;Future&lt;Void>> results = Lists.newArrayList();
-   *   Future<Void> f = executor.submit(new Callable<Void> {
+   *   Future&lt;Void> f = executor.submit(new Callable&lt;Void> {
    *     public Void call() {
    *       assertTrue(someMethod());
    *     }
    *   });
    *   results.add(f);
    *   assertOnFutures(results);
-   * </code>
+   * </pre>
    * @param threadResults A list of futures
-   * @param <T>
    * @throws InterruptedException If interrupted when waiting for a result
    *                              from one of the futures
    * @throws ExecutionException If an exception other than AssertionError
    *                            occurs inside any of the futures
    */
-  public static <T> void assertOnFutures(List<Future<T>> threadResults)
+  public static void assertOnFutures(List<Future<?>> threadResults)
   throws InterruptedException, ExecutionException {
-    for (Future<T> threadResult : threadResults) {
+    for (Future<?> threadResult : threadResults) {
       try {
         threadResult.get();
       } catch (ExecutionException e) {

hbase-server/src/test/java/org/apache/hadoop/hbase/TestMetaTableAccessorNoCluster.java

@@ -122,7 +122,7 @@ public class TestMetaTableAccessorNoCluster {
   /**
    * Test that MetaTableAccessor will ride over server throwing
    * "Server not running" IOEs.
-   * @see @link {https://issues.apache.org/jira/browse/HBASE-3446}
+   * @see <a href="https://issues.apache.org/jira/browse/HBASE-3446">HBASE-3446</a>
    * @throws IOException
    * @throws InterruptedException
    */

hbase-server/src/test/java/org/apache/hadoop/hbase/TestPartialResultsFromClientSide.java

@@ -603,12 +603,12 @@ public class TestPartialResultsFromClientSide {
 
   /**
    * Make puts to put the input value into each combination of row, family, and qualifier
-   * @param rows
+   * @param rows the rows to use
-   * @param families
+   * @param families the families to use
-   * @param qualifiers
+   * @param qualifiers the qualifiers to use
-   * @param value
+   * @param value the values to use
-   * @return
+   * @return the dot product of the given rows, families, qualifiers, and values
-   * @throws IOException
+   * @throws IOException if there is a problem creating one of the Put objects
    */
   static ArrayList<Put> createPuts(byte[][] rows, byte[][] families, byte[][] qualifiers,
       byte[] value) throws IOException {
@@ -632,11 +632,11 @@ public class TestPartialResultsFromClientSide {
   /**
    * Make key values to represent each possible combination of family and qualifier in the specified
    * row.
-   * @param row
+   * @param row the row to use
-   * @param families
+   * @param families the families to use
-   * @param qualifiers
+   * @param qualifiers the qualifiers to use
-   * @param value
+   * @param value the values to use
-   * @return
+   * @return the dot product of the given families, qualifiers, and values for a given row
    */
   static ArrayList<Cell> createKeyValuesForRow(byte[] row, byte[][] families, byte[][] qualifiers,
       byte[] value) {
@@ -772,9 +772,9 @@ public class TestPartialResultsFromClientSide {
   /**
    * Exhausts the scanner by calling next repetitively. Once completely exhausted, close scanner and
    * return total cell count
-   * @param scanner
+   * @param scanner the scanner to exhaust
-   * @return
+   * @return the number of cells counted
-   * @throws Exception
+   * @throws Exception if there is a problem retrieving cells from the scanner
    */
   private int countCellsFromScanner(ResultScanner scanner) throws Exception {
     Result result = null;

hbase-server/src/test/java/org/apache/hadoop/hbase/backup/TestHFileArchiving.java

@@ -425,9 +425,9 @@ public class TestHFileArchiving {
 
   /**
    * Get the names of all the files below the given directory
-   * @param fs
+   * @param fs the file system to inspect
-   * @param archiveDir
+   * @param archiveDir the directory in which to look
-   * @return
+   * @return a list of all files in the directory and sub-directories
    * @throws IOException
    */
   private List<String> getAllFileNames(final FileSystem fs, Path archiveDir) throws IOException {

hbase-server/src/test/java/org/apache/hadoop/hbase/client/HConnectionTestingUtility.java

@@ -50,7 +50,7 @@ public class HConnectionTestingUtility {
   /**
    * Get a Mocked {@link ClusterConnection} that goes with the passed <code>conf</code>
    * configuration instance.  Minimally the mock will return
-   * <code>conf</conf> when {@link ClusterConnection#getConfiguration()} is invoked.
+   * &lt;code>conf&lt;/conf> when {@link ClusterConnection#getConfiguration()} is invoked.
    * Be sure to shutdown the connection when done by calling
    * {@link Connection#close()} else it will stick around; this is probably not what you want.
    * @param conf configuration
@@ -148,7 +148,7 @@ public class HConnectionTestingUtility {
    * @param conf configuration
    * @return ClusterConnection object for <code>conf</code>
    * @throws ZooKeeperConnectionException
-   * @see @link
+   * [Dead link]: See also
    * {http://mockito.googlecode.com/svn/branches/1.6/javadoc/org/mockito/Mockito.html#spy(T)}
    */
   public static ClusterConnection getSpiedConnection(final Configuration conf)

hbase-server/src/test/java/org/apache/hadoop/hbase/filter/TestColumnRangeFilter.java

@@ -24,9 +24,15 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
-import org.apache.hadoop.hbase.*;
+
+import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.HBaseClassTestRule;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.KeyValue;
+import org.apache.hadoop.hbase.KeyValueTestUtil;
+import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.Durability;
 import org.apache.hadoop.hbase.client.Put;
 import org.apache.hadoop.hbase.client.Result;
@@ -91,6 +97,24 @@ class StringRange {
     return hashCode;
   }
 
+  @Override
+  public boolean equals(Object obj) {
+    if (this == obj) {
+      return true;
+    }
+    if (obj == null) {
+      return false;
+    }
+    if (!(obj instanceof StringRange)) {
+      return false;
+    }
+    StringRange oth = (StringRange) obj;
+    return this.startInclusive == oth.startInclusive &&
+        this.endInclusive == oth.endInclusive &&
+        Objects.equals(this.start, oth.start) &&
+        Objects.equals(this.end, oth.end);
+  }
+
   @Override
   public String toString() {
     String result = (this.startInclusive ? "[" : "(")
@@ -133,33 +157,21 @@ public class TestColumnRangeFilter {
   @Rule
   public TestName name = new TestName();
 
-  /**
-   * @throws java.lang.Exception
-   */
   @BeforeClass
   public static void setUpBeforeClass() throws Exception {
     TEST_UTIL.startMiniCluster();
   }
 
-  /**
-   * @throws java.lang.Exception
-   */
   @AfterClass
   public static void tearDownAfterClass() throws Exception {
     TEST_UTIL.shutdownMiniCluster();
   }
 
-  /**
-   * @throws java.lang.Exception
-   */
   @Before
   public void setUp() throws Exception {
     // Nothing to do.
   }
 
-  /**
-   * @throws java.lang.Exception
-   */
   @After
   public void tearDown() throws Exception {
     // Nothing to do.

hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/KVGenerator.java

@@ -22,7 +22,7 @@ import org.apache.hadoop.io.BytesWritable;
 import org.apache.hadoop.io.WritableComparator;
 
 /**
- * Generate random <key, value> pairs.
+ * Generate random &lt;key, value> pairs.
  * <p>
  * Copied from
  * <a href="https://issues.apache.org/jira/browse/HADOOP-3315">hadoop-3315 tfile</a>.

hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestRegionPlacement.java

@@ -401,7 +401,7 @@ public class TestRegionPlacement {
   /**
    * Verify the number of user regions is assigned to the primary
    * region server based on the plan is expected
-   * @param expectedNum.
+   * @param expectedNum the expected number of assigned regions
    * @throws IOException
    */
   private void verifyRegionOnPrimaryRS(int expectedNum)
@@ -536,9 +536,8 @@ public class TestRegionPlacement {
 
   /**
    * Create a table with specified table name and region number.
-   * @param tablename
+   * @param tableName the name of the table to be created
-   * @param regionNum
+   * @param regionNum number of regions to create
-   * @return
    * @throws IOException
    */
   private static void createTable(TableName tableName, int regionNum)

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestCompoundBloomFilter.java

@@ -124,7 +124,7 @@ public class TestCompoundBloomFilter {
   private FileSystem fs;
   private BlockCache blockCache;
 
-  /** A message of the form "in test#<number>:" to include in logging. */
+  /** A message of the form "in test#&lt;number>:" to include in logging. */
   private String testIdMsg;
 
   private static final int GENERATION_SEED = 2319;

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestHRegion.java

@@ -5925,7 +5925,7 @@ public class TestHRegion {
   /**
    * Utility method to setup a WAL mock.
    * Needs to do the bit where we close latch on the WALKeyImpl on append else test hangs.
-   * @return
+   * @return a mock WAL
    * @throws IOException
    */
   private WAL mockWAL() throws IOException {

hbase-server/src/test/java/org/apache/hadoop/hbase/snapshot/SnapshotTestingUtils.java

@@ -274,9 +274,9 @@ public final class SnapshotTestingUtils {
    * Helper method for testing async snapshot operations. Just waits for the
    * given snapshot to complete on the server by repeatedly checking the master.
    *
-   * @param master: the master running the snapshot
+   * @param master the master running the snapshot
-   * @param snapshot: the snapshot to check
+   * @param snapshot the snapshot to check
-   * @param sleep: amount to sleep between checks to see if the snapshot is done
+   * @param sleep amount to sleep between checks to see if the snapshot is done
    * @throws ServiceException if the snapshot fails
    * @throws org.apache.hbase.thirdparty.com.google.protobuf.ServiceException
    */
@@ -357,7 +357,7 @@ public final class SnapshotTestingUtils {
   /**
    * List all the HFiles in the given table
    *
-   * @param fs: FileSystem where the table lives
+   * @param fs FileSystem where the table lives
    * @param tableDir directory of the table
    * @return array of the current HFiles in the table (could be a zero-length array)
    * @throws IOException on unexecpted error reading the FS

hbase-server/src/test/java/org/apache/hadoop/hbase/util/HFileArchiveTestingUtil.java

@@ -140,7 +140,7 @@ public class HFileArchiveTestingUtil {
   }
 
   /**
-   * @return <expected, gotten, backup>, where each is sorted
+   * @return &lt;expected, gotten, backup&gt;, where each is sorted
    */
   private static List<List<String>> getFileLists(FileStatus[] previous, FileStatus[] archived) {
     List<List<String>> files = new ArrayList<>(3);

hbase-server/src/test/java/org/apache/hadoop/hbase/util/TestRegionSplitter.java

@@ -423,7 +423,7 @@ public class TestRegionSplitter {
     }
 
     /**
-     * List.indexOf() doesn't really work for a List<byte[]>, because byte[]
+     * List.indexOf() doesn't really work for a List&lt;byte[]>, because byte[]
      * doesn't override equals(). This method checks whether a list contains
      * a given element by checking each element using the byte array
      * comparator.

pom.xml

@@ -1500,7 +1500,7 @@
     <asciidoctorj.pdf.version>1.5.0-alpha.15</asciidoctorj.pdf.version>
     <build.helper.maven.version>3.0.0</build.helper.maven.version>
     <buildnumber.maven.version>1.4</buildnumber.maven.version>
-    <checkstyle.version>6.18</checkstyle.version>
+    <checkstyle.version>8.2</checkstyle.version>
     <exec.maven.version>1.6.0</exec.maven.version>
     <error-prone.version>2.2.0</error-prone.version>
     <findbugs-annotations>1.3.9-1</findbugs-annotations>
@@ -1509,7 +1509,7 @@
     <lifecycle.mapping.version>1.0.0</lifecycle.mapping.version>
     <maven.antrun.version>1.8</maven.antrun.version>
     <maven.bundle.version>3.3.0</maven.bundle.version>
-    <maven.checkstyle.version>2.17</maven.checkstyle.version>
+    <maven.checkstyle.version>3.0.0</maven.checkstyle.version>
     <maven.compiler.version>3.6.1</maven.compiler.version>
     <maven.dependency.version>3.0.1</maven.dependency.version>
     <maven.eclipse.version>2.10</maven.eclipse.version>