HBASE-25223 Use try-with-resources statement (#2592)

Signed-off-by: Wei-Chiu Chuang <weichiu@apache.org>
Signed-off-by: Viraj Jasani <vjasani@apache.org>
Signed-off-by: Duo Zhang <zhangduo@apache.org>
Signed-off-by: stack <stack@apache.org>

hbase-server/src/main/java/org/apache/hadoop/hbase/snapshot/CreateSnapshot.java

@@ -67,24 +67,13 @@ public class CreateSnapshot extends AbstractHBaseTool {
 
     @Override
     protected int doWork() throws Exception {
-        Connection connection = null;
+        try (Connection connection = ConnectionFactory.createConnection(getConf());
-        Admin admin = null;
+              Admin admin = connection.getAdmin()) {
-        try {
-            connection = ConnectionFactory.createConnection(getConf());
-            admin = connection.getAdmin();
           admin.snapshot(new SnapshotDescription(snapshotName, tableName, snapshotType));
         } catch (Exception e) {
           System.err.println("failed to take the snapshot: " + e.getMessage());
           return -1;
-        } finally {
-            if (admin != null) {
-                admin.close();
-            }
-            if (connection != null) {
-                connection.close();
-            }
         }
       return 0;
     }
-
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/snapshot/SnapshotDescriptionUtils.java

@@ -343,13 +343,8 @@ public final class SnapshotDescriptionUtils {
     FsPermission perms = CommonFSUtils.getFilePermissions(fs, fs.getConf(),
       HConstants.DATA_FILE_UMASK_KEY);
     Path snapshotInfo = new Path(workingDir, SnapshotDescriptionUtils.SNAPSHOTINFO_FILE);
-    try {
+    try (FSDataOutputStream out = CommonFSUtils.create(fs, snapshotInfo, perms, true)){
-      FSDataOutputStream out = CommonFSUtils.create(fs, snapshotInfo, perms, true);
-      try {
       snapshot.writeTo(out);
-      } finally {
-        out.close();
-      }
     } catch (IOException e) {
       // if we get an exception, try to remove the snapshot info
       if (!fs.delete(snapshotInfo, false)) {
@@ -370,15 +365,8 @@ public final class SnapshotDescriptionUtils {
   public static SnapshotDescription readSnapshotInfo(FileSystem fs, Path snapshotDir)
       throws CorruptedSnapshotException {
     Path snapshotInfo = new Path(snapshotDir, SNAPSHOTINFO_FILE);
-    try {
+    try (FSDataInputStream in = fs.open(snapshotInfo)){
-      FSDataInputStream in = null;
+      return SnapshotDescription.parseFrom(in);
-      try {
-        in = fs.open(snapshotInfo);
-        SnapshotDescription desc = SnapshotDescription.parseFrom(in);
-        return desc;
-      } finally {
-        if (in != null) in.close();
-      }
     } catch (IOException e) {
       throw new CorruptedSnapshotException("Couldn't read snapshot info from:" + snapshotInfo, e);
     }
@@ -434,12 +422,10 @@ public final class SnapshotDescriptionUtils {
   }
 
   public static boolean isSecurityAvailable(Configuration conf) throws IOException {
-    try (Connection conn = ConnectionFactory.createConnection(conf)) {
+    try (Connection conn = ConnectionFactory.createConnection(conf); Admin admin = conn.getAdmin()) {
-      try (Admin admin = conn.getAdmin()) {
       return admin.tableExists(PermissionStorage.ACL_TABLE_NAME);
     }
   }
-  }
 
   private static SnapshotDescription writeAclToSnapshotDescription(SnapshotDescription snapshot,
       Configuration conf) throws IOException {

hbase-server/src/main/java/org/apache/hadoop/hbase/snapshot/SnapshotManifest.java

@@ -582,11 +582,8 @@ public final class SnapshotManifest {
    */
   private void writeDataManifest(final SnapshotDataManifest manifest)
       throws IOException {
-    FSDataOutputStream stream = workingDirFs.create(new Path(workingDir, DATA_MANIFEST_NAME));
+    try (FSDataOutputStream stream = workingDirFs.create(new Path(workingDir, DATA_MANIFEST_NAME))) {
-    try {
       manifest.writeTo(stream);
-    } finally {
-      stream.close();
     }
   }
 
@@ -594,9 +591,7 @@ public final class SnapshotManifest {
    * Read the SnapshotDataManifest file
    */
   private SnapshotDataManifest readDataManifest() throws IOException {
-    FSDataInputStream in = null;
+    try (FSDataInputStream in = workingDirFs.open(new Path(workingDir, DATA_MANIFEST_NAME))) {
-    try {
-      in = workingDirFs.open(new Path(workingDir, DATA_MANIFEST_NAME));
       CodedInputStream cin = CodedInputStream.newInstance(in);
       cin.setSizeLimit(manifestSizeLimit);
       return SnapshotDataManifest.parseFrom(cin);
@@ -604,8 +599,6 @@ public final class SnapshotManifest {
       return null;
     } catch (InvalidProtocolBufferException e) {
       throw new CorruptedSnapshotException("unable to parse data manifest " + e.getMessage(), e);
-    } finally {
-      if (in != null) in.close();
     }
   }
 

hbase-server/src/main/java/org/apache/hadoop/hbase/snapshot/SnapshotManifestV2.java

@@ -93,12 +93,9 @@ public final class SnapshotManifestV2 {
       FileSystem workingDirFs = snapshotDir.getFileSystem(this.conf);
       if (workingDirFs.exists(snapshotDir)) {
         SnapshotRegionManifest manifest = region.build();
-        FSDataOutputStream stream = workingDirFs.create(
+        try (FSDataOutputStream stream = workingDirFs.create(
-            getRegionManifestPath(snapshotDir, manifest));
+            getRegionManifestPath(snapshotDir, manifest))) {
-        try {
           manifest.writeTo(stream);
-        } finally {
-          stream.close();
         }
       } else {
         LOG.warn("can't write manifest without parent dir, maybe it has been deleted by master?");
@@ -157,14 +154,10 @@ public final class SnapshotManifestV2 {
       completionService.submit(new Callable<SnapshotRegionManifest>() {
         @Override
         public SnapshotRegionManifest call() throws IOException {
-          FSDataInputStream stream = fs.open(st.getPath());
+          try (FSDataInputStream stream = fs.open(st.getPath())) {
             CodedInputStream cin = CodedInputStream.newInstance(stream);
             cin.setSizeLimit(manifestSizeLimit);
-
-          try {
             return SnapshotRegionManifest.parseFrom(cin);
-          } finally {
-            stream.close();
           }
         }
       });