zookeeper 客户端操作

代码

 1 /**
 2  * 创建zk客户端
 3  * 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
 4  * @author tele
 5  *
 6  */
 7 public class Demo {
 8     private int sessionTimeout = 2000;
 9     //多个节点用逗号隔开
10     private String connectString="hadoop002:2181,hadoop003:2181";
11     private ZooKeeper zkClient;
12     
13     /**
14      * 初始化
15      * @throws IOException
16      */
17     @Before
18     public void init() throws IOException {
19         zkClient = new ZooKeeper(connectString, sessionTimeout,new Watcher(){
20             @Override
21             public void process(WatchedEvent event) {
22                 try {
23                     //实现循环监听
24                     List<String> list = zkClient.getChildren("/",true);
25                 } catch (KeeperException e) {
26                     e.printStackTrace();
27                 } catch (InterruptedException e) {
28                     e.printStackTrace();
29                 }
30                 System.out.println(event.getType() + "	" + "path:" + event.getPath());
31                 
32             }
33         });
34     }
35     
36     
37     /**
38      * 创建节点
39      * @throws InterruptedException 
40      * @throws KeeperException 
41      */
42     @Test
43     public void createNode() throws KeeperException, InterruptedException {
44         String nodeName = zkClient.create("/wycrencaiss","ok".getBytes(),Ids.OPEN_ACL_UNSAFE,CreateMode.PERSISTENT_SEQUENTIAL);
45         System.out.println("创建的节点名称是-----" + nodeName);
46     }
47     
48     
49     
50     /**
51      * 获取节点
52      * @throws InterruptedException 
53      * @throws KeeperException 
54      */
55     @Test
56     public void getNode() throws KeeperException, InterruptedException {
57         List<String> list = zkClient.getChildren("/",true);
58         for (String string : list) {
59             System.out.println(string);
60         }
61         
62         Thread.sleep(Long.MAX_VALUE);
63     }
64     
65     
66     /**
67      * 判断节点是否存在
68      * @throws InterruptedException 
69      * @throws KeeperException 
70      */
71     @Test
72     public void isExist() throws KeeperException, InterruptedException {
73         
74         Stat stat = zkClient.exists("/wyc",true);
75         System.out.println(stat==null?"not exist":"exist");
76         Thread.sleep(Long.MAX_VALUE);
77     }
78 }

maven

 1 <dependency>
 2       <groupId>org.apache.zookeeper</groupId>
 3       <artifactId>zookeeper</artifactId>
 4       <version>3.4.10</version>
 5 </dependency>
 6 <dependency>
 7       <groupId>junit</groupId>
 8       <artifactId>junit</artifactId>
 9       <version>4.11</version>
10       <scope>test</scope>
11 </dependency>