zooKeeper API 简单应用

zooKeeper API 简单应用


zooKeeperTest.java

package com;
import java.util.Arrays; 
public class zooKeeperTest{ 
 
	public static void main(String[] args) {  
        try {  
            ZooKeeperOperator zkoperator             = new ZooKeeperOperator();  
            zkoperator.connect("114.55.72.173:2181");  
            byte[] data = new byte[]{'d','a','t','a'};  
              
            zkoperator.create("/root",null);  
            System.out.println(Arrays.toString(zkoperator.getData("/root")));  
              
            zkoperator.create("/root/child4",data);  
            System.out.println(Arrays.toString(zkoperator.getData("/root/child1")));  
              
            zkoperator.create("/root/child3",data);  
            System.out.println(Arrays.toString(zkoperator.getData("/root/child2")));  
              
            System.out.println("节点孩子信息:");  
            zkoperator.getChild("/root");  
              
            zkoperator.close();  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
    }  
} 

AbstractZooKeeper.java

package com;
import java.io.IOException;  
import java.util.concurrent.CountDownLatch;  
import org.apache.zookeeper.WatchedEvent;  
import org.apache.zookeeper.Watcher;  
import org.apache.zookeeper.ZooKeeper;  
import org.apache.zookeeper.Watcher.Event.KeeperState;  
  
public class AbstractZooKeeper implements Watcher {  
    private static final int SESSION_TIME   = 2000;  
    protected ZooKeeper  zooKeeper;  
    protected CountDownLatch countDownLatch = new CountDownLatch(1);  
  
    public void connect(String hosts) throws IOException, InterruptedException{  
        zooKeeper = new ZooKeeper(hosts,SESSION_TIME,this);  
        countDownLatch.await();  
    }  
    public void process(WatchedEvent event) {  
        if(event.getState() == KeeperState.SyncConnected){  
            countDownLatch.countDown();  
        }  
    }  
    public void close() throws InterruptedException{  
        zooKeeper.close();  
    }  
}  

ZooKeeperOperator.java

package com;
import java.util.Arrays;  
import java.util.List;  
import org.apache.zookeeper.CreateMode;  
import org.apache.zookeeper.KeeperException;  
import org.apache.zookeeper.ZooDefs.Ids;  
  
public class ZooKeeperOperator extends AbstractZooKeeper {  
    /** 
     * 创建持久态的znode,比支持多层创建.比如在创建/parent/child的情况下,无/parent.无法通过. 
     * @param path eg:  /parent/child1 
     * @param data 
     * @throws InterruptedException  
     * @throws KeeperException  
     */  
    public void create(String path,byte[] data) throws KeeperException, InterruptedException{  
        this.zooKeeper.create(path, data, Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT/*此处创建的为持久态的节点,可为瞬态*/);  
    }  
      
    /** 
     * 获取节点的孩子信息 
     * @param path 
     * @throws KeeperException 
     * @throws InterruptedException 
     */  
    public void getChild(String path) throws KeeperException, InterruptedException{  
        try {  
            List<String> children = this.zooKeeper.getChildren(path, false);  
            if (children.isEmpty()) {  
                System.out.printf("没有节点在%s中.", path);  
                return;  
            }else{  
                System.out.printf("节点%s中存在的节点:\n", path);  
                for(String child: children){  
                    System.out.println(child);  
                }  
            }  
        } catch (KeeperException.NoNodeException e) {  
            System.out.printf("%s节点不存在.", path);  
            throw e;  
        }  
    }  
  
    public byte[] getData(String path) throws KeeperException, InterruptedException {  
        return  this.zooKeeper.getData(path, false,null);  
    }  
}  

参考原文： http://okwangxing.iteye.com/blog/598548