MAPREDUCE-6431. JobClient should be an AutoClosable (haibochen via rkanter)

hadoop-mapreduce-project/CHANGES.txt

@@ -311,6 +311,8 @@ Release 2.9.0 - UNRELEASED
 
   IMPROVEMENTS
 
+    MAPREDUCE-6431. JobClient should be an AutoClosable (haibochen via rkanter)
+
   OPTIMIZATIONS
 
   BUG FIXES

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-common/src/test/java/org/apache/hadoop/mapred/TestJobClient.java

@@ -87,4 +87,14 @@ public class TestJobClient {
         client.getClusterHandle().getStagingAreaDir().toString()
             .equals(client.getStagingAreaDir().toString()));
   }
+
+  /**
+   * Asks the compiler to check if JobClient is AutoClosable.
+   */
+  @Test(timeout = 10000)
+  public void testAutoClosable() throws IOException {
+    Configuration conf = new Configuration();
+    try (JobClient jobClient = new JobClient(conf)) {
+    }
+  }
 }

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/JobClient.java

@@ -137,7 +137,7 @@ import org.apache.hadoop.util.ToolRunner;
  */
 @InterfaceAudience.Public
 @InterfaceStability.Stable
-public class JobClient extends CLI {
+public class JobClient extends CLI implements AutoCloseable {
 
   @InterfaceAudience.Private
   public static final String MAPREDUCE_CLIENT_RETRY_POLICY_ENABLED_KEY =
@@ -499,6 +499,7 @@ public class JobClient extends CLI {
   /**
    * Close the <code>JobClient</code>.
    */
+  @Override
   public synchronized void close() throws IOException {
     cluster.close();
   }