开发者学堂课程【分布式协调系统 Zookeeper 快速入门：服务器节点动态上下线案例全部代码实现】学习笔记，与课程紧密联系，让用户快速学习知识。
课程地址：https://developer.aliyun.com/learning/course/97/detail/1597
服务器节点动态上下线案例全部代码实现
服务端代码相当于把服务器注册到集群中，有几个节点就有几个服务器
客户端代码
package com. atquiqu. zkcase;
import java. io. IOException;
import java.util. Arraylist;
import java.util.List;
import org. apache . zookeeper . Wa tchedEvent;
.import org. apache . zookeeper . Watcher;
import orq. apache . zookeeper . ZooKeeper;
public class Distribrteclient ｛
private static String connectString
"hadoop102: 2181, hadoop103:2181, hadoop104:2181";-private static int sessionTimeout = 2000;
private ZooKeeper zk = null;
private String parentNode = " servers";
main 方法中还要注意几步
DistributeClient client = new DistributeClient();
11 1 获取 zookeeper 集群连接
client. getConnect();l
// 2注册监听
client. getchlidren();
11 3 业务逻辑处理
private void getChlidren() throws KeeperException, InterruptedException (
List<string> children = zkClient. getChildren(" /servers", true);
//存储服务器节点主机名称集合
ArrayList<string> hosts = new ArrayList<>();
for (String child : children) (
byte[] data = zkClient. getData("/servers/"+child, false, null);
hosts . add(new String(data));
11 将所有在线主机名称打印到控制台
System.out.println(hosts);
