zookeeper的javaAPI使用

前提:
1.虚拟机之间互通。
2.windows环境的host域名解析配置完成     C:WINDOWSsystem32driversetchost
3.java引入以下maven jar包

    
        org.apache.curator
        curator-framework
        2.12.0
    
    
        org.apache.curator
        curator-recipes
        2.12.0
    
    
        com.google.collections
        google-collections
        1.0
    
    
        org.junit.jupiter
        junit-jupiter
        RELEASE
        
        test
    


    
        
        
            org.apache.maven.plugins
            maven-compiler-plugin
            3.2
            
                1.8
                1.8
                UTF-8
            
        
    

---------------------------------------以下为具体代码-------------------------
package cn.itcast_zk.demo01;

import org.apache.curator.RetryPolicy;
import org.apache.curator.RetrySleeper;
import org.apache.curator.framework.Curatorframework;
import org.apache.curator.framework.CuratorframeworkFactory;
import org.apache.curator.framework.recipes.cache.ChildData;
import org.apache.curator.framework.recipes.cache.TreeCache;
import org.apache.curator.framework.recipes.cache.TreeCacheEvent;
import org.apache.curator.framework.recipes.cache.TreeCacheListener;
import org.apache.curator.retry.ExponentialBackoffRetry;
import org.apache.zookeeper.CreateMode;
import org.junit.jupiter.api.Test;

public class zkOperate {
    @Test
    public  void  createNode() throws Exception {
        //创建一个客户连接
        RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000,2);

        Curatorframework client = CuratorframeworkFactory.newClient("node01:2181,node02:2181,node03:2181",retryPolicy);

        //启动连接
        client.start();

        //这个客户递归创建一个节点，节点类型为永久，路径为/java_node_test01/hello,内容为asdb
        client.create().creatingParentsIfNeeded().withMode(CreateMode.PERSISTENT).forPath("/java_node_test01/hello","asdb".getBytes());

        //结束
        client.close();


    }

    @Test
    public  void  createNode2() throws Exception {
        RetryPolicy retryPolicy = new ExponentialBackoffRetry(100000,2);

        Curatorframework client = CuratorframeworkFactory.newClient("node01:2181,node02:2181,node03:2181",retryPolicy);

        client.start();

        //这个客户递归创建一个节点，节点类型为临时，路径为/java_node_test01/hello,内容为asdb
        client.create().creatingParentsIfNeeded().withMode(CreateMode.EPHEMERAL).forPath("/java_node_test02/hello");

        Thread.sleep(5000);

        client.close();


    }

    @Test
    public  void  updateNode() throws Exception {
        RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000,2);

        Curatorframework client = CuratorframeworkFactory.newClient("node01:2181,node02:2181,node03:2181",retryPolicy);

        client.start();
        //这个客户递归设置/java_node_test01的值为test
        client.setData().forPath("/java_node_test01","test".getBytes());


        client.close();


    }

    @Test
    public  void  delteNode() throws Exception {
        RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000,2);

        Curatorframework client = CuratorframeworkFactory.newClient("node01:2181,node02:2181,node03:2181",retryPolicy);

        client.start();

        client.delete().forPath("/java_node_test01");


        client.close();


    }

    @Test
    public  void  getNode() throws Exception {
        RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000,2);

        Curatorframework client = CuratorframeworkFactory.newClient("node01:2181,node02:2181,node03:2181",retryPolicy);

        client.start();
        
        //获取节点的值
        byte[] bs = client.getData().forPath("/java_node_test01");
        System.out.println(new String(bs));


        client.close();


    }

    @Test
    public void watch() throws Exception {
        RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000,2);
        Curatorframework client = CuratorframeworkFactory.newClient("node01:2181,node02:2181,node03:2181",retryPolicy);



        client.start();

        //创建一个节点的监听,此监听不是一次性的，用完会自动再次注册
        TreeCache treeCache = new TreeCache(client,"/");

        //重写监听的方法，注意入参Curatorframework client, TreeCacheEvent even，和入参的方法getData();getType();
        treeCache.getListenable().addListener(new TreeCacheListener() {
            @Override
            public void childEvent(Curatorframework client, TreeCacheEvent even) throws Exception {
                ChildData data = even.getData();
                if(data != null){
                    System.out.println(even.getType());
                    switch ( even.getType()){
                        case  NODE_ADDED:
                            System.out.println("节点增加内容是:"+new String(data.getData())+";路径是:"+data.getPath());
                            break;
                        case NODE_UPDATED:
                            System.out.println("NODE_UPDATED : "+ data.getPath() +"  数据:"+ new String(data.getData()));
                            break;
                        case NODE_REMOVED:
                            System.out.println("NODE_REMOVED : "+ data.getPath() +"  数据:"+ new String(data.getData()));
                            break;
                        default:
                            break;
                    }

                }else {
                    System.out.println("data is null : "+ even.getType());
                }

            }
        });
        
        //启动监听
        treeCache.start();
        
        //当前线程休眠待机
        Thread.sleep(500000);
        client.close();
    }
}