zookeeper的java客户端api（增删改查）

package zookeeper_java;

import java.util.List;

import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.data.Stat;
import org.junit.Before;
import org.junit.Test;

public class SimpleZkClient {
	
    //写三个，一个连不上还可以连其它的
	private static final String connectString ="node1:2181,node2:2181,node3:2181";
	private static final int sessionTimeout=2000; //设置超时时间为2秒
	ZooKeeper zkClient=null;
	
	@Before
	public void  init() throws Exception {
		zkClient=new ZooKeeper(connectString, sessionTimeout, new Watcher() {
			@Override
			public void process(WatchedEvent event) {
				// 收到事件通知后的回调函数，事件处理逻辑
				//事件类型和事件路径（节点）
				System.out.println(event.getType()+"-------"+event.getPath());
				//可实现反复监听
				try {
					zkClient.getChildren("/", true);
				} catch (Exception e) {	
					e.printStackTrace();
				}
			}
		} );
	}
		
		/**
		 * 数据的增删改查
		 * @throws Exception 
		 * @throws KeeperException 
		 */
	
	//创建数据节点到zk中
   
	public void testCreate() throws Exception {
		//1.路径 2.写入的data 3.权限，开放给所有人 4.节点类别，持久的
		String nodeCreated= zkClient.create("/eclipse", "hello zookeeper".getBytes(),
				Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
		//上传的数据可以是任何数据，但都要转成byte[]数组
	}
		
	//判断节点是否存在

	public void testExist() throws Exception{
		//节点下的数据就封装在stat中
		Stat stat = zkClient.exists("/eclipse", false);
        System.out.println(stat==null?"not exist":"exist");
	}
	
  //获取子节点
  
	public void getChildren() throws Exception {
		//getChildren相当于linux中的ls /,所以监听的是节点的变化	
		List<String> children = zkClient.getChildren("/", true);
		for (String child : children) {
			System.out.println(child);
		}
		
	}
		
       //获取node数据
      
       public void getData() throws Exception {
	     byte[] data = zkClient.getData("/eclipse", null, null);
	     System.out.println(new String(data));
      }
		
		
       //删除node数据
     
       public void delData() throws Exception {
    	  //-1表示删除所有版本的数据 
	     zkClient.delete("/eclipse", -1);
      }
		
       //更改node数据
       @Test
       public void setData() throws Exception {
    	  zkClient.setData("/app1", "i miss you !!!".getBytes(), -1);	
	     byte[] data = zkClient.getData("/app1", null, null);
	     System.out.println(new String(data));
      }
		
       
}