1、安装zookeeper

下载zk http://archive.cloudera.com/cdh5/cdh/5/

配置文件tickTime=2000

initLimit=10

syncLimit=5

# zk数据保存目录

dataDir=/usr/local/zookeeper/data

clientPort=2181

启动：

bin/zkServer.sh start

客户端命令行链接：

bin/zkCli.sh

2、拷贝zookeeper下的jar包，到应用程序，并使用maven引入相关jar包

org.slf4j

slf4j-api

1.7.25

org.apache.zookeeper

zookeeper

3.4.5-cdh5.10.0

system

${project.basedir}/lib/zookeeper-3.4.5-cdh5.10.0.jar

java 代码import org.apache.zookeeper.CreateMode;

import org.apache.zookeeper.WatchedEvent;

import org.apache.zookeeper.Watcher;

import org.apache.zookeeper.Watcher.Event.EventType;

import org.apache.zookeeper.ZooDefs.Ids;

import org.apache.zookeeper.ZooKeeper;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

public class ZookeeperContext {

protected static Logger logger = LoggerFactory.getLogger("zk");

public final int SESSION_TIME_OUT = 2000;

public ZooKeeper zk;

/**

* 判断zk的链接链接状态

* */

public boolean isConnected(){

return zk.getState() == ZooKeeper.States.CONNECTED;

}

/**

* 创建zk链接

* **/

public ZookeeperContext(String connectString) {

try {

/**

* connectString 链接zookeeper的Ip和端口，多个用逗号隔开例如：

* 10.0.0.104:2181,10.0.0.105:2181 sessionTimeout

* 客户端和zookeeper链接断开后，数据最长保存的时间 watcher 监控回调，服务器数据修改会回调

*/

zk = new ZooKeeper(connectString, SESSION_TIME_OUT, new ZookeeperWatcher());

} catch (Exception e) {

e.printStackTrace();

}

}

/**

* zk监听，如果服务器端有什么变化到这里接收

* 并继续添加监听

* */

public class ZookeeperWatcher implements Watcher {

@Override

public void process(WatchedEvent event) {

try {

if(null != event.getPath()){

System.out.println( event );

if(event.getType() == EventType.NodeChildrenChanged){

zk.getChildren(event.getPath(), true) ;

}else{

zk.getData(event.getPath(), true, null) ;

}

}

} catch (Exception e) {

e.printStackTrace();

}

}

}

/**

* 在zk创建数据

* */

public void setData(String path,byte[]data , CreateMode createMode){

try {

if(zk.exists(path, false) == null){

zk.create(path, data, Ids.OPEN_ACL_UNSAFE, createMode) ;

}else{

zk.setData(path,data,-1);

}

zk.getChildren(path, true) ;

} catch (Exception e) {

logger.error("setData", e );

}

}

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

ZookeeperContext context = new ZookeeperContext("10.0.0.104:2181");

while (!context.isConnected()) {

Thread.sleep(3000);

}

context.setData("/root", "1".getBytes(),CreateMode.PERSISTENT);

context.setData("/root/hpgary", "gg".getBytes() , CreateMode.EPHEMERAL);

System.err.println("eee");

System.in.read() ;

}

}

项目运行截图：