Zookeeper学习(五)：ZKClient的使用

1.创建会话

public class createSession {

	public static void main(String[] args) {
		//zk集群的地址
		String ZKServers = "192.168.30.164:2181,192.168.30.165:2181,192.168.30.166:2181";
	
		/**
		 * 创建会话
		 * new SerializableSerializer() 创建序列化器接口，用来序列化和反序列化
		 */
		ZkClient zkClient = new ZkClient(ZKServers,10000,10000,new SerializableSerializer());
		
		System.out.println("conneted ok!");
		
	}
}

2.创建节点

public class createNode {

	public static void main(String[] args) {
		//zk集群的地址
		String ZKServers = "192.168.30.164:2181,192.168.30.165:2181,192.168.30.166:2181";
		ZkClient zkClient = new ZkClient(ZKServers,10000,10000,new SerializableSerializer());
		
		System.out.println("conneted ok!");
		
		User user = new User();
		user.setId(1);
		user.setName("testUser");
		
		/**
		 * "/testUserNode" :节点的地址
		 * user：数据的对象
		 * CreateMode.PERSISTENT：创建的节点类型
		 */
		String path = zkClient.create("/testUserNode", user, CreateMode.PERSISTENT);
		//输出创建节点的路径
		System.out.println("created path:"+path);
	}
}

//注意：一定要实现序列化接口  implements Serializable
public class User implements Serializable{
	
	private Integer id;
	private String name;
	
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
}

3.获取节点中的数据

public class getData {
	public static void main(String[] args) {
		        //zk集群的地址
				String ZKServers = "192.168.30.164:2181,192.168.30.165:2181,192.168.30.166:2181";
				ZkClient zkClient = new ZkClient(ZKServers,10000,10000,new SerializableSerializer());
				System.out.println("conneted ok!");
				
				Stat stat = new Stat();
				//获取 节点中的对象
				User  user = zkClient.readData("/testUserNode",stat);
				System.out.println(user.getName());
				System.out.println(stat);
	}
}

4.判断节点是否存在

public class getData {
	public static void main(String[] args) {
		        //zk集群的地址
				String ZKServers = "192.168.30.164:2181,192.168.30.165:2181,192.168.30.166:2181";
				ZkClient zkClient = new ZkClient(ZKServers,10000,10000,new SerializableSerializer());
				System.out.println("conneted ok!");
				
				boolean e = zkClient.exists("/testUserNode");
				//返回 true表示节点存在 ，false表示不存在
				System.out.println(e);
	}
}

5.删除节点

public class getData {
	public static void main(String[] args) {
		        //zk集群的地址
				String ZKServers = "192.168.30.164:2181,192.168.30.165:2181,192.168.30.166:2181";
				ZkClient zkClient = new ZkClient(ZKServers,10000,10000,new SerializableSerializer());
				System.out.println("conneted ok!");
				
				//删除单独一个节点，返回true表示成功
				boolean e1 = zkClient.delete("/testUserNode");
				//删除含有子节点的节点
				boolean e2 = zkClient.deleteRecursive("/test");
				
				//返回 true表示节点成功 ，false表示删除失败
				System.out.println(e1);
	}
}

6.更新数据

public static void main(String[] args) {
		        //zk集群的地址
				String ZKServers = "192.168.30.164:2181,192.168.30.165:2181,192.168.30.166:2181";
				ZkClient zkClient = new ZkClient(ZKServers,10000,10000,new SerializableSerializer());
				System.out.println("conneted ok!");
				
				User user = new User();
				user.setId(2);
				user.setName("testUser2");
				/**
				 * testUserNode 节点的路径
				 * user 传入的数据对象
				 */
				zkClient.writeData("/testUserNode", user);
	}

7.订阅节点的信息改变（创建节点，删除节点，添加子节点）

public class SubscribeChildChanges {
	private static class ZKChildListener implements IZkChildListener{
        /**
         * handleChildChange： 用来处理服务器端发送过来的通知
         * parentPath：对应的父节点的路径
         * currentChilds：子节点的相对路径
         */
		public void handleChildChange(String parentPath, List<String> currentChilds) throws Exception {
			
			System.out.println(parentPath);
			System.out.println(currentChilds.toString());
			
		}
		
	}
	
	public static void main(String[] args) throws InterruptedException {
        //zk集群的地址
		String ZKServers = "192.168.30.164:2181,192.168.30.165:2181,192.168.30.166:2181";
		ZkClient zkClient = new ZkClient(ZKServers,10000,10000,new SerializableSerializer());
		System.out.println("conneted ok!");
		/**
		 * "/testUserNode" 监听的节点，可以是现在存在的也可以是不存在的
		 */
		zkClient.subscribeChildChanges("/testUserNode3", new ZKChildListener());
		Thread.sleep(Integer.MAX_VALUE);
    }
}

8.订阅节点的数据内容的变化

public class SubscribeDataChanges {
	private static class ZKDataListener implements IZkDataListener{

		public void handleDataChange(String dataPath, Object data) throws Exception {
			
			System.out.println(dataPath+":"+data.toString());
		}

		public void handleDataDeleted(String dataPath) throws Exception {
			
			System.out.println(dataPath);
			
		}
       
		
	}
	
	public static void main(String[] args) throws InterruptedException {
        //zk集群的地址
		String ZKServers = "192.168.30.164:2181,192.168.30.165:2181,192.168.30.166:2181";
		ZkClient zkClient = new ZkClient(ZKServers,10000,10000,new SerializableSerializer());
		System.out.println("conneted ok!");

		zkClient.subscribeDataChanges("/testUserNode", new ZKDataListener());
		Thread.sleep(Integer.MAX_VALUE);
		
    }
}