zookeeper 客户端操作

代码

 /**
  * 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);
     }
 }

maven

 <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>