/** * * @author zhangwei_david * @version $Id: ZKDemo.java, v 0.1 2015年5月2日 上午9:10:56 zhangwei_david Exp $ */public class ZKDemo {    private static CountDownLatch latch = new CountDownLatch(1);    private static ZooKeeper      zk    = null;    private static String         path  = "/zk-demo";    /**     *     * @param args     * @throws Exception     */    public static void main(String[] args) throws Exception {        zk = new ZooKeeper("localhost:2181", 5000, new Watcher() {            public void process(WatchedEvent event) {                if (KeeperState.SyncConnected == event.getState()) {                    //如果客户端已经建立连接闭锁减一                    latch.countDown();                }            }        });        // 等待zk实例创建完成        latch.await();        // 如果该节点不存在则创建持久化的节点        if (zk.exists(path, true) == null) {            zk.create(path, "".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);        }        //创建临时节点        zk.create(path + "/test", "test".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);        // 删除节点        zk.delete(path + "/test", 0);        // 异步创建临时节点        zk.create(path + "/test", "123".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL,            new StringCallback() {                public void processResult(int rc, String path, Object ctx, String name) {                    System.out.println("result code=" + rc + ", path=" + path + " context=" + ctx                    + ", name=" + name);                }            }, "Test Context");        TimeUnit.SECONDS.sleep(3);        // 更新数据        zk.setData(path + "/test", "testData".getBytes(), -1);        zk.create(path + "/test2", "123".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);        // 获取节点        List
     
       znodes = zk.getChildren(path, true);        // 获取所有节点下的数据        Stat stat = new Stat();        for (String str : znodes) {            byte[] data = zk.getData(path + "/" + str, true, stat);            System.out.println("获取节点：" + str + " 的数据是：" + new String(data));        }    }}