ZooKeeperConnection.java

package demo;

import java.io.IOException;
import java.util.concurrent.CountDownLatch;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.Event.KeeperState;
import org.apache.zookeeper.ZooKeeper;

/**
 * https://www.tutorialspoint.com/zookeeper/zookeeper_api.htm
 */
public class ZooKeeperConnection {

    private ZooKeeper zoo;
    final CountDownLatch connectedSignal = new CountDownLatch(1);

    public ZooKeeper connect(String host) throws IOException, InterruptedException {
        zoo = new ZooKeeper(host, 5000, new Watcher() {
            @Override
            public void process(WatchedEvent watchedEvent) {
                if (watchedEvent.getState() == KeeperState.SyncConnected) {
                    connectedSignal.countDown();
                }
            }
        });

        connectedSignal.await();
        return zoo;
    }

    public void close() throws InterruptedException {
        if (zoo != null) {
            zoo.close();
        }
    }
}