org.apache.flink.runtime.leaderretrieval.SettableLeaderRetrievalService 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.leaderretrieval;
import org.apache.flink.util.Preconditions;
import javax.annotation.Nullable;
import java.util.UUID;
/**
* {@link LeaderRetrievalService} implementation which directly forwards calls of
* notifyListener to the listener.
*/
public class SettableLeaderRetrievalService implements LeaderRetrievalService {
private String leaderAddress;
private UUID leaderSessionID;
private LeaderRetrievalListener listener;
public SettableLeaderRetrievalService() {
this(null, null);
}
public SettableLeaderRetrievalService(
@Nullable String leaderAddress,
@Nullable UUID leaderSessionID) {
this.leaderAddress = leaderAddress;
this.leaderSessionID = leaderSessionID;
}
@Override
public synchronized void start(LeaderRetrievalListener listener) throws Exception {
this.listener = Preconditions.checkNotNull(listener);
if (leaderSessionID != null && leaderAddress != null) {
listener.notifyLeaderAddress(leaderAddress, leaderSessionID);
}
}
@Override
public void stop() throws Exception {
}
public synchronized void notifyListener(
@Nullable String address,
@Nullable UUID leaderSessionID) {
this.leaderAddress = address;
this.leaderSessionID = leaderSessionID;
if (listener != null) {
listener.notifyLeaderAddress(address, leaderSessionID);
}
}
}