my-zookeeper.zip

package com.example; import java.io.IOException; import org.apache.log4j.Logger; import org.apache.zookeeper.CreateMode; import org.apache.zookeeper.KeeperException; import org.apache.zookeeper.WatchedEvent; import org.apache.zookeeper.Watcher; import org.apache.zookeeper.ZooDefs.Ids; import org.apache.zookeeper.ZooKeeper; import org.apache.zookeeper.data.Stat; /** * * @Description: idea此处为Client端，CentOS为ZooKeeper的Server端 * * 1.通过java程序，新建链接zk，类似jdbc的connection，open.session * 2.新建一个znode节点/atguigu并设置为hello1018 等同于create /atguigu hello1018 * 3.获得当前节点/atguigu的最新值 get /atguigu * 4.关闭链接 * * @author zzyy * @date 2018年3月21日 */ public class HelloZK { /** * Logger for this class */ private static final Logger logger = Logger.getLogger(HelloZK.class); //实例常量 private static final String CONNECTSTRING = "127.0.0.1:2181";//139.196.90.125 private static final String PATH = "/my-node"; private static final int SESSION_TIMEOUT = 20 * 1000; //实例变量 private ZooKeeper zk; /** * @throws IOException * @Title: startZK * @Description: 获得ZK的连接实例 * @param @return 参数 * @return ZooKeeper 返回类型 * @throws */ public ZooKeeper startZK() throws IOException { return new ZooKeeper(CONNECTSTRING, SESSION_TIMEOUT, new Watcher() { public void process(WatchedEvent watchedEvent) { } }); } /** * * @Title: createZnode * @Description: 创建一个节点并赋值 * @param @param zk * @param @param path * @param @param data * @param @throws KeeperException * @param @throws InterruptedException 参数 * @return void 返回类型 * @throws */ public void createZnode(ZooKeeper zk,String path,String data) throws KeeperException, InterruptedException { zk.create(path, data.getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT); } /** * * @Title: getZnode * @Description: 获得节点的值 * @param @param zk * @param @param path * @param @return * @param @throws KeeperException * @param @throws InterruptedException 参数 * @return String 返回类型 * @throws */ public String getZnode(ZooKeeper zk,String path) throws KeeperException, InterruptedException { String result = ""; byte[] byteArray = zk.getData(path, false, new Stat()); result = new String(byteArray); return result; } /** * * @Title: stopZK * @Description:关闭连接 * @param @param zk * @param @throws InterruptedException 参数 * @return void 返回类型 * @throws */ public void stopZK(ZooKeeper zk) throws InterruptedException { if(null != zk) zk.close(); } public static void main(String[] args) throws Exception { HelloZK hello = new HelloZK(); ZooKeeper zk = hello.startZK(); if(zk.exists(PATH, false) == null) { hello.createZnode(zk, PATH, "hello world!"); String result = hello.getZnode(zk, PATH); if (logger.isInfoEnabled()) { logger.info("main(String[]) ***************** String result=" + result); } }else { logger.info("This node is exists......"); } hello.stopZK(zk); } }