Zookeeper入门开发demo

package CreateGroup;



import java.io.IOException;

import java.util.List;

import java.util.concurrent.CountDownLatch;



import org.apache.zookeeper.AsyncCallback;

import org.apache.zookeeper.AsyncCallback.Children2Callback;

import org.apache.zookeeper.AsyncCallback.ChildrenCallback;

import org.apache.zookeeper.AsyncCallback.StatCallback;

import org.apache.zookeeper.CreateMode;

import org.apache.zookeeper.KeeperException;

import org.apache.zookeeper.WatchedEvent;

import org.apache.zookeeper.Watcher;

import org.apache.zookeeper.Watcher.Event.KeeperState;

import org.apache.zookeeper.ZooDefs.Ids;

import org.apache.zookeeper.ZooKeeper;

import org.apache.zookeeper.data.Stat;

import org.apache.zookeeper.server.ConnectionBean;





public class TestZkGroup implements Watcher {

	private static final int SESSION_TIMEOUT = 5000;

	

	private ZooKeeper zk;

	private CountDownLatch connectedSignal = new CountDownLatch(2);

	Childwatcher childwatcher = new Childwatcher(); 

	

	private void getthreadname(String funname){

		Thread current = Thread.currentThread();  

		System.out.println(funname + " is call in  " + current.getName());

	}

	

	@Override

	// 运行在另外一个线程 main-EventThread

	public void process(WatchedEvent event) {

		getthreadname("process");

		System.out.println((event.getType()));  // 打印状态

		

		if (event.getState() == KeeperState.SyncConnected){

			connectedSignal.countDown();

		}

	}

	

	// 测试自定义监听

	public Watcher wh = new Watcher() {

		public void process(WatchedEvent event) {

			getthreadname("Watcher::process");

			System.out.println("回调watcher实例： 路径" + event.getPath() + " 类型："

			+ event.getType());

		}

	};

	

	public void connect(String hosts) throws IOException, InterruptedException{

		getthreadname("connect");

		zk = new ZooKeeper(hosts, SESSION_TIMEOUT, wh); // 最后一个参数用this会调用自身的监听  wh 代表？

		//connectedSignal.await(); // 主线程挂起

	}

	

	// 加入组(可以理解成一个创建本次连接的一个组)

	public void join(String groupname, String meberName) throws KeeperException, InterruptedException{

		 String path = "/" + groupname + "/" + meberName ;

        

        

		// EPHEMERAL断开将被删除

		String createdpath = zk.create(path, null, Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);

		System.out.println("join : " + createdpath);

	}

	

    public List<String> getChilds(String path) throws KeeperException, InterruptedException {  

        // TODO Auto-generated method stub  

        if (zk != null) {  

            // return zk.getChildren(path, false); // false表示没有设置观察 

        	//zk.getChildren(path, true, childwatcher.processResult, null);

        	zk.getChildren( path, true, new AsyncCallback.Children2Callback() {

				@Override

				public void processResult(int rc, String path, Object ctx,

						List<String> children, Stat stat) { // stat参数代表元数据

					// TODO Auto-generated method stub

					System.out.println("****");

				  	for (int i = 0; i < children.size() - 1; i ++){

		        		System.out.println("mempath = " + children.get(i) + stat);

		        	}	

				}

    }, null);

        	

        }  

        return null;  

    }  

	

	public void create(String path) throws KeeperException, InterruptedException, IOException{

		// Ids.OPEN_ACL_UNSAFE 开放式ACL，允许任何客户端对znode进行读写

		// CreateMode.PERSISTENT 持久的znode，本次连接断开后还会存在，应该有持久化操作.

		// PERSISTENT_SEQUENTIAL 持久化顺序，这个由zookeeper来保证

		

		String createdpath = zk.create(path, null, Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);

		System.out.println("crateed : " + createdpath);    

	}

	

	private void close() throws InterruptedException{

		if  (zk != null){

			zk.close();

		}

	}

	

	public static class Childwatcher implements Children2Callback{

		public ChildrenCallback processResult;



		@Override

		public void processResult(int rc, String path, Object ctx,

				List<String> children, Stat stat) {

			// TODO Auto-generated method stub

			System.out.println("**** path " + stat);

		}

	}

	

	public void delete(String groupname) throws InterruptedException, KeeperException{		

		zk.delete(groupname, -1);

	}

	

	public Stat isexist(String groupname) throws InterruptedException, KeeperException{		

		return zk.exists(groupname, true); // this

	}

	

	 public void write(String path, String value)throws Exception{  

         Stat stat=zk.exists(path, false);  

         if(stat==null){  

             zk.create(path, value.getBytes("UTF-8"), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);  

         }else{  

               

             zk.setData(path, value.getBytes("UTF-8"), -1);  

         }      

     }  

	 

	 public String read(String path,Watcher watch)throws Exception{  

         byte[] data=zk.getData(path, watch, null);             

         return new String(data, "UTF-8");  

     }  



	public static void main(String[] args) throws Exception {	

		String hosts = "localhost";

		String groupname = "zktest" ;

		String meberName = String.valueOf(System.currentTimeMillis());

		String path = "/" + groupname;

		

		// create

		TestZkGroup test = new TestZkGroup();

		//  连接

		test.connect(hosts);

		// 

	    if (null != test.isexist(path)){

	    	test.delete(path);

	    }

		

		test.isexist(path);

        test.create(path);

        

        test.isexist(path);

        test.write(path, "test");

        

        test.isexist(path);

        String result = test.read(path, test.wh);

        System.out.println(path + " value = " + result);

        

        int sum = 0;

        for (int j = 0 ; j< 10000; j++){

        	sum++;

        	Thread.sleep(10);

        }

        System.out.println(sum);

        test.close();

   

      System.exit(2);

		// 一个本地连接的znode

		test.connect(hosts);

        test.join(groupname, meberName);

        

        // 遍历

        List<String> memlist = test.getChilds("/" + "zktest" );

        if (memlist != null){

        	for (int i = 0; i < memlist.size() - 1; i ++){

        		System.out.println("mempath = " + memlist.get(i));

        	}

        }

	}

}