zookeeper 应用开发

由于zookeeper的client只有zookeeper一个对象，使用也比较简单，所以就不许要文字说明了，在代码中注释下就ok 了。

1、测试用的main方法

package ClientExample;

public class TestMain {
 public static void main(String[] args) {
        /*
         * 测试流程
         * 1、创建sever1的连接client1，并且创建一个永久性的/test节点
         * 2、创建一个针对server1的临时节点
         * 3、创建server2的连接client21，并创建一个针对server2的临时节点
         * 4、创建server3的连接client3，并创建一个针对server3的临时节点
         * 5、分别查看client1、client2、client3的三个节点的字节点数量，确定是否同步成功
         * 6、修改client1的临时节点内容，然后在在client2和client3中查看
         * 7、kill掉client3的线程，然后检查是watcher是否有通知给client1和client2
         */  

         Thread t1= new ClientThread("127.0.0.1:2181","server1",false);
         Thread t2= new ClientThread("127.0.0.1:2182","server2",false);
         Thread t3= new ClientThread("127.0.0.1:2183","server3",false);
         Thread t4= new ClientThread("127.0.0.1:2181","server4",false);  

         t1.start();
         t2.start();
         t3.start();
         t4.start();
         ControlThread c = new ControlThread(t1, t2, t3, t4);
         c.start();
         int i=0;
         while(true)
         {
            i++;
            i--;  

         }  

         /*
          * 测试控制台输出：
          * connectIP:server4,path:null,state:SyncConnected,type:None
          * connectIP:server3,path:/test,state:SyncConnected,type:NodeChildrenChanged
          * connectIP:server4,path:/test/server4,state:SyncConnected,type:NodeCreated
          * 。。。。。。。。。。。
          *
          * connectIP:server2,path:null,state:Disconnected,type:None
            server2exception,KeeperErrorCode = ConnectionLoss for /test
            connectIP:newServer1,path:null,state:SyncConnected,type:None
            connectIP:server1,path:/test,state:SyncConnected,type:NodeChildrenChanged
            connectIP:server4,path:/test/server2,state:SyncConnected,type:NodeDeleted
            connectIP:server4,path:/test,state:SyncConnected,type:NodeChildrenChanged
            connectIP:newServer1,path:/test,state:SyncConnected,type:NodeChildrenChanged
            connectIP:server3,path:/test/server2,state:SyncConnected,type:NodeDeleted
            connectIP:server3,path:/test,state:SyncConnected,type:NodeChildrenChanged
          */
    }
}

2、zookeeper封装的接口：

package ClientExample;

import java.io.IOException;
import java.util.List;
import org.apache.zookeeper.KeeperException;
/**
 * zookeeper的操作封装接口，实现了常用的操作
 * 创建、销毁、写入、修改、查询等。
 * @author ransom
 *
 */
public interface ServerOperation {
    void init(String address,String serverName) throws IOException;
    void destroy() throws InterruptedException;
    List<String> getChilds(String path) throws KeeperException,
            InterruptedException;
    String getData(String path) throws KeeperException, InterruptedException;
    void changeData(String path, String data) throws KeeperException,
            InterruptedException;
    void delData(String path) throws KeeperException, InterruptedException;
    void apendTempNode(String path, String data) throws KeeperException,
            InterruptedException;
    void apendPresistentNode(String path, String data) throws KeeperException,
    InterruptedException;  

    void delNode(String path) throws KeeperException, InterruptedException;
    boolean exist(String path) throws KeeperException, InterruptedException;
}

3、接口的实现：

package ClientExample;

import java.io.IOException;
import java.util.List;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.ZooDefs.Ids;
public class ServerConnector implements ServerOperation {
    // 创建一个Zookeeper实例，第一个参数为目标服务器地址和端口，第二个参数为Session超时时间，第三个为节点变化时的回调方法
    private ZooKeeper zk = null;
    public void init(String address,String serverName) throws IOException {
        zk = new ZooKeeper(address, 500000,
                new MultiWatcher(serverName));
    }
    @Override
    public void destroy() throws InterruptedException {
        // TODO Auto-generated method stub
        if (zk != null) {
            zk.close();
        }
    }
    @Override
    public List<String> getChilds(String path) throws KeeperException, InterruptedException {
        // TODO Auto-generated method stub
        if (zk != null) {
            return zk.getChildren(path, true);
        }
        return null;
    }
    @Override
    public String getData(String path) throws KeeperException, InterruptedException {
        // TODO Auto-generated method stub
        if (zk != null) {
            // 取得/root/childone节点下的数据,返回byte[]
            byte[] b = zk.getData(path, true, null);
            return new String(b);
        }
        return null;
    }
    @Override
    public void changeData(String path,String data) throws KeeperException, InterruptedException {
        // TODO Auto-generated method stub
        if (zk != null) {
            // 修改节点/root/childone下的数据，第三个参数为版本，如果是-1，那会无视被修改的数据版本，直接改掉
            zk.setData(path, data.getBytes(),-1);
        }
    }
    @Override
    public void delData(String path) throws InterruptedException, KeeperException {
        // TODO Auto-generated method stub
        if (zk != null) {
            // 删除/root/childone这个节点，第二个参数为版本，－1的话直接删除，无视版本
            zk.delete(path, -1);
        }
    }
    @Override
    public void delNode(String path) throws InterruptedException, KeeperException {
        // TODO Auto-generated method stub
        if (zk != null) {
            zk.delete(path, -1);
        }
    }
    @Override
    public boolean exist(String path) throws KeeperException,
            InterruptedException {
        // TODO Auto-generated method stub
        if (zk != null) {
            return zk.exists(path, true)!=null;
        }
        return false;
    }
    @Override
    public void apendTempNode(String path, String data) throws KeeperException,
            InterruptedException {
        // TODO Auto-generated method stub
        // TODO Auto-generated method stub
        if (zk != null)
        {
            // 创建一个节点root，数据是mydata,不进行ACL权限控制，节点为永久性的(即客户端shutdown了也不会消失)
            /*
             * 创建一个给定的目录节点 path, 并给它设置数据，
             * CreateMode 标识有四种形式的目录节点,分别是
             * PERSISTENT：持久化目录节点，这个目录节点存储的数据不会丢失；
             * PERSISTENT_SEQUENTIAL：顺序自动编号的目录节点，这种目录节点会根据当前已近存在的节点数自动加 1，然后返回给客户端已经成功创建的目录节点名；
             * EPHEMERAL：临时目录节点，一旦创建这个节点的客户端与服务器端口也就是 session 超时，这种节点会被自动删除；
             * EPHEMERAL_SEQUENTIAL：临时自动编号节点
             */
            zk.create(path, data.getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);
        }
    }
    @Override
    public void apendPresistentNode(String path, String data)
            throws KeeperException, InterruptedException {
        // TODO Auto-generated method stub
        if (zk != null)
        {
            // 创建一个节点root，数据是mydata,不进行ACL权限控制，节点为永久性的(即客户端shutdown了也不会消失)
            /*
             * 创建一个给定的目录节点 path, 并给它设置数据，
             * CreateMode 标识有四种形式的目录节点,分别是
             * PERSISTENT：持久化目录节点，这个目录节点存储的数据不会丢失；
             * PERSISTENT_SEQUENTIAL：顺序自动编号的目录节点，这种目录节点会根据当前已近存在的节点数自动加 1，然后返回给客户端已经成功创建的目录节点名；
             * EPHEMERAL：临时目录节点，一旦创建这个节点的客户端与服务器端口也就是 session 超时，这种节点会被自动删除；
             * EPHEMERAL_SEQUENTIAL：临时自动编号节点
             */
            zk.create(path, data.getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
        }
    }
}  

4、一个控制的线程，主要用来强制kill掉连接的线程

package ClientExample;

public class ControlThread extends Thread{
    public ControlThread(Thread t1,Thread t2,Thread t3,Thread t4)
    {
        list[0]=t1;
        list[1]=t2;
        list[2]=t4;
        list[3]=t4;
    }  

    private Thread[] list = new Thread[4];
    private int num=0;
    public void run()
    {
        while(true)
        {
            if(num==7)
            {
                list[2].stop();
                System.out.println("kill server3");
            }
            if(num==15)
            {
                list[3].stop();
                System.out.println("kill server4");
            }
            try {
                sleep(1000);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
}

5、watcher 的实现：

package ClientExample;

import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.Event.EventType;
import org.apache.zookeeper.Watcher.Event.KeeperState;
/**
 * 提供给多个client使用的watcher
 * @author ransom
 *
 */
public class MultiWatcher implements Watcher{
    public MultiWatcher(String address)
    {
        connectAddress=address;
    }  

    private String connectAddress=null;  

    @Override
    public void process(WatchedEvent event) {
        // TODO Auto-generated method stub
        String outputStr="";
        if(connectAddress!=null){
            outputStr+="connectIP:"+connectAddress;
        }
        outputStr+=",path:"+event.getPath();
        outputStr+=",state:"+event.getState();
        outputStr+=",type:"+event.getType();  

        System.out.println(outputStr);
    }
}

6、client 运行 的Thread

package ClientExample;

import java.io.IOException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import org.apache.zookeeper.KeeperException;
public class ClientThread extends Thread{
    public ClientThread(String address,String serverName,boolean islog)
    {
        this.address=address;
        this.serverName=serverName;
        try {
            otherOperation();
        } catch (KeeperException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        this.islog=islog;
    }
    private boolean islog=true;
    private final String rootPath = "/test";
    private String address;
    private String serverName;
    private ServerOperation operationCient = null;  

    public void run()
    {
        if(operationCient==null)
        {
            System.out.println("operationCient=null");
            return;
        }  

        while(true){
            try {
                if(islog){
                    System.out.println(serverName+",loopTime:"+getNowTime());
                }
                observerChildData(rootPath);
            } catch (KeeperException e) {
                // TODO Auto-generated catch block
                System.out.println(serverName+"exception,"+e.getLocalizedMessage());
                try {
                    operationCient= new ServerConnector();
                    operationCient.init("127.0.0.1:2181","newServer1");
                } catch (IOException e1) {
                    // TODO Auto-generated catch block
                    System.out.println(serverName+" reconnect  exception,"+e.getLocalizedMessage());
                }
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            try {
                sleep(2000);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }  

    }  

    /*
     * 测试流程
     * 1、创建sever1的连接client1，并且创建一个永久性的/test节点
     * 2、创建一个针对server1的临时节点
     * 3、创建server2的连接client21，并创建一个针对server2的临时节点
     * 4、创建server3的连接client3，并创建一个针对server3的临时节点
     * 5、分别查看client1、client2、client3的三个节点的字节点数量，确定是否同步成功
     * 6、修改client1的临时节点内容，然后在在client2和client3中查看
     * 7、kill掉client3的线程，然后检查是watcher是否有通知给client1和client2
     */  

    private void otherOperation() throws KeeperException, InterruptedException
    {
        operationCient= new ServerConnector();
        try {
            operationCient.init(address,serverName);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }  

        if(operationCient==null)
        {
            System.out.println("operationCient=null");
            return;
        }
        if(!operationCient.exist(rootPath))
        {
            operationCient.apendPresistentNode(rootPath, "this node is creat by " + serverName);
        }  

        //添加临时节点
        if(!operationCient.exist(rootPath+"/"+serverName))
        {
            operationCient.apendTempNode(rootPath+"/"+serverName,  "this node is creat by " + serverName);
        }
        observerChildData("/test");  

        //修改临时节点内容
        operationCient.changeData(rootPath+"/"+serverName, "this node is changed by " + serverName);
        //临时节点内容
        List<String> childs=operationCient.getChilds(rootPath);
        for(String str : childs)
        {
            System.out.println("observered by "+ serverName +": child node is :"+ str);
        }  

    }  

    //查看临时节点的同步状态
    public void observerChildData(String path) throws KeeperException, InterruptedException
    {
        if(operationCient==null)
        {
            System.out.println("operationCient=null");
            return;
        }  

        List<String> childs=operationCient.getChilds(rootPath);
        if(islog){
            System.out.println("observered by "+ serverName +": childs len is :"+ childs.size());
        }
        for(String str : childs)
        {
            if(islog){
                System.out.println("observered by "+ serverName +": child node is :"+ str+",data is :"+operationCient.getData(rootPath+"/"+str));
            }
        }  

    }
    public String getNowTime()
    {
        DateFormat format1 = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
        return format1.format(new Date());
    }  

}