客户端的API操作

前提：保证hadoop102、hadoop103、hadoop104服务器上Zookeeper集群服务端启动

客户端的API操作

IDEA环境搭建创建ZooKeeper客户端

1.创建一个maven工程

2.添加pom文件

    
        
            junit
            junit
            RELEASE
        
        
            org.apache.logging.log4j
            log4j-core
            2.8.2
        
        
            org.apache.zookeeper
            zookeeper
            3.5.7
        
 	

3.拷贝log4j.properties文件到项目根目录

在src/main/resources目录下，新建一个文件log4j.properties，内容为:

log4j.rootLogger=INFO, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] - %m%n
log4j.appender.logfile=org.apache.log4j.FileAppender
log4j.appender.logfile.File=target/spring.log
log4j.appender.logfile.layout=org.apache.log4j.PatternLayout
log4j.appender.logfile.layout.ConversionPattern=%d %p [%c] - %m%n 

package com.yingzi.zk;

import org.apache.zookeeper.*;
import org.apache.zookeeper.data.Stat;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;
import java.util.List;


public class zkClient {

    //    //注意：逗号前后不能有空格
    private static String connectString = "hadoop102:2181,hadoop103:2181,hadoop104:2181";
    private static int sessionTimeout = 2000;
    private ZooKeeper zkClient = null;

    @Before
    public void init() throws IOException {
        zkClient = new ZooKeeper(connectString, sessionTimeout, new Watcher() {
            @Override
            public void process(WatchedEvent watchedEvent) {

//                System.out.println("------------------------------");
//                List children = null;
//                try {
//                    children = zkClient.getChildren("/", true);
//
//                    for (String child : children) {
//                        System.out.println(child);
//                    }
//
//                    System.out.println("------------------------------");
//                } catch (KeeperException e) {
//                    e.printStackTrace();
//                } catch (InterruptedException e) {
//                    e.printStackTrace();
//                }
            }
        });
    }

    //创建子节点
    @Test
    public void create() throws InterruptedException, KeeperException {
        String nodeCreated = zkClient.create("/yingzi", "ss.avi".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
    }

    //获取子节点
    @Test
    public void getChildern() throws InterruptedException, KeeperException {
        List children = zkClient.getChildren("/", true);

        for (String child : children) {
            System.out.println(child);
        }

        //  延时阻塞
        Thread.sleep(Long.MAX_VALUE);
    }

    //判断节点是否存在
    @Test
    public void exist() throws InterruptedException, KeeperException {
        Stat stat = zkClient.exists("/yingzi", false);

        System.out.println(stat == null ? "not exist":"exist");
    }

}