package com.kiddcorp.zk;

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;

/**
 *
 * @author jwkidd3
 *
 */
public class ZooKeeperConnection {

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

	/*
	 * Here CountDownLatch is used to stop (wait) the main process until the
	 * client connects with the ZooKeeper ensemble.
	 *
	 * The ZooKeeper ensemble replies the connection status through the Watcher
	 * callback. The Watcher callback will be called once the client connects
	 * with the ZooKeeper ensemble and the Watcher callback calls the countDown
	 * method of the CountDownLatch to release the lock, await in the main
	 * process.
	 */
	public ZooKeeper connect(String host) throws IOException, InterruptedException {

		zoo = new ZooKeeper(host, 5000, new Watcher() {

			public void process(WatchedEvent we) {

				if (we.getState() == KeeperState.SyncConnected) {
					connectedSignal.countDown();
				}
			}
		});

		connectedSignal.await();
		return zoo;
	}

	public void close() throws InterruptedException {
		zoo.close();
	}

	public static void main(String[] args) {
		ZooKeeper zk;
		ZooKeeperConnection conn;

		conn = new ZooKeeperConnection();
		try {
			zk = conn.connect("localhost:2183");
			System.out.println(zk.getSessionId());
			zk.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}