pom

<!-- zookeeper -->
<dependency>
    <groupId>org.apache.zookeeper</groupId>
    <artifactId>zookeeper</artifactId>
    <version>3.4.12</version>
</dependency>

demo

import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.data.Stat;
import java.util.concurrent.CountDownLatch;
import org.apache.zookeeper.Watcher.Event.*;
 
public class ZooKeeperProSync implements Watcher {
    private static CountDownLatch connectedSemaphore = new CountDownLatch(1);
    private static ZooKeeper zk = null;
    private static Stat stat = new Stat();
 
    @Override
    public void process(WatchedEvent event) {
        if (KeeperState.SyncConnected == event.getState()) {  //zk连接成功通知事件
            if (EventType.None == event.getType() && null == event.getPath()) {
                connectedSemaphore.countDown();
            } else if (event.getType() == EventType.NodeDataChanged) {  //zk目录节点数据变化通知事件
                try {
                    System.out.println("配置已修改,新值为:" + new String(zk.getData(event.getPath(), true, stat)));
                } catch (Exception e) {
                }
            }
        }
    }
 
    public static void main(String[] args) throws Exception {
        //zookeeper配置数据存放路径
        String path = "/username";
        //连接zookeeper并且注册一个默认的监听器
        zk = new ZooKeeper("47.108.77.227:2181", 5000,
                new ZooKeeperProSync());
        //等待zk连接成功的通知
        connectedSemaphore.await();
        //获取path目录节点的配置数据,并注册默认的监听器
        System.out.println(new String(zk.getData(path, true, stat)));
 
        Thread.sleep(Integer.MAX_VALUE);
    }
}