1：刪除節點API

• 必須先刪除葉子節點，才能再刪除根節點

2：引數說明

3：程式碼樣例

package LearningZK;

import java.util.concurrent.CountDownLatch;

import org.apache.zookeeper.*;
import org.apache.zookeeper.Watcher.Event.KeeperState;
import org.apache.zookeeper.ZooDefs.Ids;

public class UsingZookeeperAPI implements Watcher{

    private static CountDownLatch connectedSemaphore = new CountDownLatch(1);

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

        /*使用ZK構造方法例項化ZK物件來建立會話*/
        /*new UsingZookeeperAPI 實現watcher介面，重寫process方法,處理服務端返回的非同步通知*/
        ZooKeeper zookeeper = new ZooKeeper("172.21.10.136:2181",
                5000,
                new UsingZookeeperAPI());

        System.out.println(zookeeper.getState());
//        long sessionID = zookeeper.getSessionId();     //獲取會話ID
//        byte[] sessionPasswd = zookeeper.getSessionPasswd(); //獲取會話金鑰
        try {
            connectedSemaphore.await();
        } catch (InterruptedException e) {}
        System.out.println("ZooKeeper session established.");

        /*以同步的方式建立ZK臨時節點*/
        String path1 = zookeeper.create("/ZK_test", "".getBytes(),Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);
        System.out.println("Create Znode Success:"+path1);

        /*以同步的方式建立ZK臨時順序節點*/
        String path2 = zookeeper.create("/ZK_test","".getBytes(),Ids.OPEN_ACL_UNSAFE,CreateMode.EPHEMERAL_SEQUENTIAL);
        System.out.println("Create Znode Succsess:"+path2);

        /*以非同步的方式建立ZK臨時節點*/
        zookeeper.create("/ZK_test_async", "".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL, new AsyncCallBack(), "I am content");

        /*以同步的方式刪除ZK節點*/
        zookeeper.delete("/ZK_test", -1);  //-1表示任何版本
        System.out.println("Delete Znode Success");

        /*以非同步的方式刪除ZK節點*/
        //zookeeper.delete("/ZK_test",-1,new IsCallback(),"content");


        Thread.sleep(Integer.MAX_VALUE);
    }

    /*處理ZK服務端watcher通知，再接收到服務端發來的SyncConnected通知後，解除主程式的等待阻塞*/
    public void process(WatchedEvent event) {
        System.out.println("Receive watched event:" + event);
        if (KeeperState.SyncConnected == event.getState()) {
            connectedSemaphore.countDown();
        }
    }
}

/*非同步建立節點回調方法簡單實現*/
class AsyncCallBack implements AsyncCallback.StringCallback{
    public void processResult(int rc,  String path,  Object ctx,  String name){
        System.out.println("Create path result:["+rc+","+path+","+ctx+",real path name"+name);
    }
}

/*非同步刪除節點回調方法簡單實現*/
class IsCallback implements AsyncCallback.VoidCallback{
    public void processResult(int rc, String path, Object ctx){
        System.out.println("rc:"+rc+"path:"+path+"Object:"+ctx);
    }
}