/**

  * 创建zk客户端

  * 实现循环监听的两个必要条件:1.程序不能结束2.递归调用监听器

  * @author tele

  *

  */

 public class Demo {

     private int sessionTimeout = ;

     //多个节点用逗号隔开

     private String connectString="hadoop002:2181,hadoop003:2181";

     private ZooKeeper zkClient;

     /**

      * 初始化

      * @throws IOException

      */

     @Before

     public void init() throws IOException {

         zkClient = new ZooKeeper(connectString, sessionTimeout,new Watcher(){

             @Override

             public void process(WatchedEvent event) {

                 try {

                     //实现循环监听

                     List<String> list = zkClient.getChildren("/",true);

                 } catch (KeeperException e) {

                     e.printStackTrace();

                 } catch (InterruptedException e) {

                     e.printStackTrace();

                 }

                 System.out.println(event.getType() + "\t" + "path:" + event.getPath());

             }

         });

     }

     /**

      * 创建节点

      * @throws InterruptedException

      * @throws KeeperException

      */

     @Test

     public void createNode() throws KeeperException, InterruptedException {

         String nodeName = zkClient.create("/wycrencaiss","ok".getBytes(),Ids.OPEN_ACL_UNSAFE,CreateMode.PERSISTENT_SEQUENTIAL);

         System.out.println("创建的节点名称是-----" + nodeName);

     }

     /**

      * 获取节点

      * @throws InterruptedException

      * @throws KeeperException

      */

     @Test

     public void getNode() throws KeeperException, InterruptedException {

         List<String> list = zkClient.getChildren("/",true);

         for (String string : list) {

             System.out.println(string);

         }

         Thread.sleep(Long.MAX_VALUE);

     }

     /**

      * 判断节点是否存在

      * @throws InterruptedException

      * @throws KeeperException

      */

     @Test

     public void isExist() throws KeeperException, InterruptedException {

         Stat stat = zkClient.exists("/wyc",true);

         System.out.println(stat==null?"not exist":"exist");

         Thread.sleep(Long.MAX_VALUE);

     }

 }

 <dependency>

       <groupId>org.apache.zookeeper</groupId>

       <artifactId>zookeeper</artifactId>

       <version>3.4.</version>

 </dependency>

 <dependency>

       <groupId>junit</groupId>

       <artifactId>junit</artifactId>

       <version>4.11</version>

       <scope>test</scope>

 </dependency>