[FLINK-32010][runtime] Leader election/retrieval drivers should prope…

…rly extend AutoCloseable instead of having their own close method with the same signature.

flink-runtime/src/main/java/org/apache/flink/runtime/leaderelection/LeaderElectionDriver.java

@@ -28,7 +28,7 @@
  * <p><strong>Important</strong>: The {@link LeaderElectionDriver} could not guarantee that there is
  * no {@link LeaderElectionEventHandler} callbacks happen after {@link #close()}.
  */
-public interface LeaderElectionDriver {
+public interface LeaderElectionDriver extends AutoCloseable {
 
     /**
      * Write the current leader information to external persistent storage(e.g. Zookeeper,
@@ -49,7 +49,4 @@ public interface LeaderElectionDriver {
      * @return Return whether the driver has leadership.
      */
     boolean hasLeadership();
-
-    /** Close the services used for leader election. */
-    void close() throws Exception;
 }

flink-runtime/src/main/java/org/apache/flink/runtime/leaderretrieval/LeaderRetrievalDriver.java

@@ -25,8 +25,4 @@
  * <p><strong>Important</strong>: The {@link LeaderRetrievalDriver} could not guarantee that there
  * is no {@link LeaderRetrievalEventHandler} callbacks happen after {@link #close()}.
  */
-public interface LeaderRetrievalDriver {
-
-    /** Close the services used for leader retrieval. */
-    void close() throws Exception;
-}
+public interface LeaderRetrievalDriver extends AutoCloseable {}

flink-runtime/src/test/java/org/apache/flink/runtime/leaderelection/TestingLeaderElectionEventHandler.java

@@ -31,7 +31,7 @@
  * testing purposes.
  */
 public class TestingLeaderElectionEventHandler extends TestingLeaderBase
-        implements LeaderElectionEventHandler {
+        implements LeaderElectionEventHandler, AutoCloseable {
 
     private final Object lock = new Object();
 
@@ -135,6 +135,7 @@ public LeaderInformation getConfirmedLeaderInformation() {
         }
     }
 
+    @Override
     public void close() {
         synchronized (lock) {
             running = false;