org.apache.flink.runtime.minicluster.OneTimeLeaderListenerFuture Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* 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
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* 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.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.flink.runtime.minicluster;
import org.apache.flink.runtime.leaderelection.LeaderAddressAndId;
import org.apache.flink.runtime.leaderretrieval.LeaderRetrievalListener;
import java.util.UUID;
import java.util.concurrent.CompletableFuture;
/**
* A leader listener that exposes a future for the first leader notification.
*
* The future can be obtained via the {@link #future()} method.
*/
public class OneTimeLeaderListenerFuture implements LeaderRetrievalListener {
private final CompletableFuture future;
public OneTimeLeaderListenerFuture() {
this.future = new CompletableFuture<>();
}
/**
* Gets the future that is completed with the leader address and ID.
* @return The future.
*/
public CompletableFuture future() {
return future;
}
// ------------------------------------------------------------------------
@Override
public void notifyLeaderAddress(String leaderAddress, UUID leaderSessionID) {
future.complete(new LeaderAddressAndId(leaderAddress, leaderSessionID));
}
@Override
public void handleError(Exception exception) {
future.completeExceptionally(exception);
}
}