如何使用Java操作Zookeeper

	com.101tec
	zkclient
	0.11

@Test
public void testCreateNode() {
	//建立连接
	//zkServers: Zookeeper服务器IP地址和端口号，如果是集群情况下用逗号分割多个Zookeeper服务器地址
	//sessionTimeout: 会话超时时间
	//connectionTimeout: 连接超时时间
	ZkClient zkClient = new ZkClient("127.0.0.1:2181", 60000, 5000);

	//创建数据
	Student student = new Student();
	student.setName("张三");
	student.setAge(18);
	student.setPhone("1585454xxxx");

	//创建持久节点
	zkClient.createPersistent("/p_node", student);
	//创建持久顺序节点
	zkClient.createPersistentSequential("/ps_node", student);
	//创建临时节点
	zkClient.createEphemeral("/e_node", student);
	//创建临时顺序节点
	zkClient.createEphemeralSequential("/ps_node", student);

	//关闭客户端
	//关闭客户端的同时，前面创建的临时节点也会被删除
	zkClient.close();
}

@Test
public void testReadNodeData() {
	ZkClient zkClient = new ZkClient("127.0.0.1:2181", 60000, 5000);

	Stat stat = new Stat();
	Student student = zkClient.readData("/p_node", stat);
	System.out.println("节点状态信息：" + JSON.toJSONString(student));
	System.out.println("节点数据：" + JSON.toJSONString(stat));

	zkClient.close();
}
//输出结果：
//节点状态信息：{"age":18,"name":"张三","phone":"1585454xxxx"}
//节点数据：{"aversion":0,"ctime":1619165355431,"cversion":0,"czxid":165,"dataLength":260,"ephemeralOwner":0,"mtime":1619165355431,"mzxid":165,"numChildren":0,"pzxid":165,"version":0}

@Test
public void testDeleteNode() {
	ZkClient zkClient = new ZkClient("127.0.0.1:2181", 60000, 5000);

	//删除节点，不能删除带有子节点的节点
	zkClient.delete("/p_node");
	//删除节点，递归删除所有子孙节点
	zkClient.deleteRecursive("/p_node2");

	zkClient.close();
}

@Test
public void testWriteNodeData() {
	ZkClient zkClient = new ZkClient("127.0.0.1:2181", 60000, 5000);

	//更新节点数据
	zkClient.writeData("/p_node", "myData1");
	//使用CAS更新节点数据
	//zkClient.writeData("/p_node", "myData2", 1);

	zkClient.close();
}

@Test
public void testGetChildNodes() {
	ZkClient zkClient = new ZkClient("127.0.0.1:2181", 60000, 5000);

	//获取子节点列表
	List childList = zkClient.getChildren("/p_node");
	childList.stream().forEach(System.out::println);

	zkClient.close();
}

@Test
public void testSubscribeChildChanges() throws IOException {
	ZkClient zkClient = new ZkClient("127.0.0.1:2181", 60000, 5000);
	zkClient.subscribeChildChanges("/p_node", new IZkChildListener(){

		//子节点改变时调用
		@Override
		public void handleChildChange(String parentPath, List currentChilds) throws Exception {
			System.out.println(parentPath + "子节点发生改变");
			System.out.println("当前子节点列表：" + currentChilds);
		}

	});

	//阻塞客户端，便于测试
	System.in.read();
}

@Test
public void testSubscribeDataChanges() throws IOException {
	ZkClient zkClient = new ZkClient("127.0.0.1:2181", 60000, 5000);
	zkClient.subscribeDataChanges("/p_node", new IZkDataListener(){

		//节点数据改变时调用
		@Override
		public void handleDataChange(String dataPath, Object data) throws Exception {
			System.out.println(dataPath + "节点数据发生变化");
			System.out.println("修改后的数据为：" + data.toString());
		}

		//节点被删除时调用
		@Override
		public void handleDataDeleted(String dataPath) throws Exception {
			System.out.println(dataPath + "节点已被删除");
		}
	});

	//阻塞客户端，便于测试
	System.in.read();
}

@Test
public void testSubscribeStateChanges() throws IOException {
	ZkClient zkClient = new ZkClient("127.0.0.1:2181", 60000, 5000);
	zkClient.subscribeStateChanges(new IZkStateListener(){

		//当zookeeper连接状态改变时调用
		@Override
		public void handleStateChanged(Watcher.Event.KeeperState state) throws Exception {
			System.out.println("当前状态" + state);
		}

		//在zookeeper会话过期并且创建了一个新的会话之后调用
		@Override
		public void handleNewSession() throws Exception {
			System.out.println("会话过期，已创建新的会话");
		}

		//当会话不能重新建立时调用
		@Override
		public void handleSessionEstablishmentError(Throwable error) throws Exception {
			error.printStackTrace();
		}
	});

	//阻塞客户端，便于测试
	System.in.read();
}