zookeeper datamonitor

ZKTest.java

package test;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.Event.EventType;
import org.apache.zookeeper.ZooKeeper;

public class ZKTest {

    private static final int SESSION_TIMEOUT = 10000;
    private static final String CONNECTION_STRING = "192.168.1.220:2181,192.168.1.220:2182,192.168.1.220:2183,192.168.1.220:2184";
    private static final String ZK_PATH = "/wx/data/access_token";

    public static void main(String[] args) throws Exception {
        final ZooKeeper zk = new ZooKeeper(CONNECTION_STRING, SESSION_TIMEOUT,
                null);

        while (true) {
            CountDownLatch c = new CountDownLatch(1);
            Watcher w = new MyWatcher(c,zk);
            zk.getData(ZK_PATH, w, null);
            TimeUnit.SECONDS.sleep(1);
            System.out.println("*");
            c.await();
        }
    }

}

class MyWatcher implements Watcher {
    private CountDownLatch c;

    private ZooKeeper zk;

    public MyWatcher(CountDownLatch c, ZooKeeper zk) {
        this.c = c;
        this.zk = zk;
    }

    @Override
    public void process(WatchedEvent event) {
        System.out.println(event.getType());
        System.out.println(event.getPath());
        System.out.println("===================");
        c.countDown();
        if (EventType.NodeDataChanged.equals(event.getType())) {
            try {
                System.out.println(new String(zk.getData(event.getPath(),
                        false, null)));
            } catch (KeeperException e) {
                e.printStackTrace();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

    }
};