Curator框架的使用

Curator框架使用链式编程风格，易读性更强，使用工厂方法创建连接对象。

1.使用CuratorFrameworkFactory的两个静态工厂方法（参数不同）来实现

参数1：connectString，连接信息

参数2：RetryPolicy，重试连接策略，有四种实现

　　ExponentialBackoffRetry、RetryNTimes、RetryOneTimes、RetryUntilElapsed

参数3：sessionTimeoutMs会话超时时间，默认为60s

参数4：connectionTimeoutMs连接超时时间，默认为15s

注意：对于retryPolicy策略通过一个接口来让用户自定义实现

 1 import java.util.List;
 2 import java.util.concurrent.ExecutorService;
 3 import java.util.concurrent.Executors;
 4 
 5 import org.apache.curator.RetryPolicy;
 6 import org.apache.curator.framework.CuratorFramework;
 7 import org.apache.curator.framework.CuratorFrameworkFactory;
 8 import org.apache.curator.framework.api.BackgroundCallback;
 9 import org.apache.curator.framework.api.CuratorEvent;
10 import org.apache.curator.retry.ExponentialBackoffRetry;
11 import org.apache.zookeeper.CreateMode;
12 import org.apache.zookeeper.ZooKeeper.States;
13 import org.apache.zookeeper.data.Stat;
14 
15 public class CuratorBase {
16     
17     /** zookeeper地址 */
18     static final String CONNECT_ADDR = "192.168.1.171:2181,192.168.1.172:2181,192.168.1.173:2181";
19     /** session超时时间 */
20     static final int SESSION_OUTTIME = 5000;//ms 
21     
22     public static void main(String[] args) throws Exception {
23         
24         //1 重试策略：初试时间为1s 重试10次
25         RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 10);
26         //2 通过工厂创建连接
27         CuratorFramework cf = CuratorFrameworkFactory.builder()
28                     .connectString(CONNECT_ADDR)
29                     .sessionTimeoutMs(SESSION_OUTTIME)
30                     .retryPolicy(retryPolicy)
31 //                    .namespace("super")
32                     .build();
33         //3 开启连接
34         cf.start();
35         
36 //        System.out.println(States.CONNECTED);
37 //        System.out.println(cf.getState());
38         
39         // 新加、删除
40         /**
41         //4 建立节点 指定节点类型（不加withMode默认为持久类型节点）、路径、数据内容
42         cf.create().creatingParentsIfNeeded().withMode(CreateMode.PERSISTENT).forPath("/super/c1","c1内容".getBytes());
43         //5 删除节点
44         cf.delete().guaranteed().deletingChildrenIfNeeded().forPath("/super");
45         */
46         
47         // 读取、修改
48         /**
49         //创建节点
50 //        cf.create().creatingParentsIfNeeded().withMode(CreateMode.PERSISTENT).forPath("/super/c1","c1内容".getBytes());
51 //        cf.create().creatingParentsIfNeeded().withMode(CreateMode.PERSISTENT).forPath("/super/c2","c2内容".getBytes());
52         //读取节点
53 //        String ret1 = new String(cf.getData().forPath("/super/c2"));
54 //        System.out.println(ret1);
55         //修改节点
56 //        cf.setData().forPath("/super/c2", "修改c2内容".getBytes());
57 //        String ret2 = new String(cf.getData().forPath("/super/c2"));
58 //        System.out.println(ret2);    
59         */
60         
61         // 绑定回调函数
62         /**
63         ExecutorService pool = Executors.newCachedThreadPool();
64         cf.create().creatingParentsIfNeeded().withMode(CreateMode.PERSISTENT)
65         .inBackground(new BackgroundCallback() {
66             @Override
67             public void processResult(CuratorFramework cf, CuratorEvent ce) throws Exception {
68                 System.out.println("code:" + ce.getResultCode());
69                 System.out.println("type:" + ce.getType());
70                 System.out.println("线程为:" + Thread.currentThread().getName());
71             }
72         }, pool)
73         .forPath("/super/c3","c3内容".getBytes());
74         Thread.sleep(Integer.MAX_VALUE);
75         */
76         
77         
78         // 读取子节点getChildren方法 和 判断节点是否存在checkExists方法
79         /**
80         List<String> list = cf.getChildren().forPath("/super");
81         for(String p : list){
82             System.out.println(p);
83         }
84         
85         Stat stat = cf.checkExists().forPath("/super/c3");
86         System.out.println(stat);
87         
88         Thread.sleep(2000);
89         cf.delete().guaranteed().deletingChildrenIfNeeded().forPath("/super");
90         */
91         
92         
93         //cf.delete().guaranteed().deletingChildrenIfNeeded().forPath("/super");
94         
95     }
96 }

Curator框架的使用

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