zookeeper客户端编程

• • 一.配置开发环境
  • 二.在 src/main/java 下新建一个OperateZK.java
  • 三.启动zookeeper
  • • 1.进入zookeeper安装目录
    • 2.启动服务(三台都要执行)

在之前的testHadoop下新建模块testZK,修改的pom.xml文件(没有之前的testhadoop的话就重新新建一个maven项目,参考java操作HDFS)

        testZK
        com.qf
        1.0-SNAPSHOT
    4.0.0

    
        
            org.apache.zookeeper
            zookeeper
            3.4.10
        
        
            junit
            junit
            4.12
        
    

    
        1.8
        1.8
    
    

文件的内容为:

import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.ZooDefs;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.data.Stat;
import org.junit.Test;


import java.nio.charset.StandardCharsets;
import java.util.List;

public class OperateZK {

    @Test
    

    public void testList() throws Exception {
        String conn = "192.168.154.10:2181,192.168.154.11:2181,192.168.154.12:2181";
        ZooKeeper zk = new ZooKeeper(conn, 5000, null);
        //列出根目录下的子节点
        List children = zk.getChildren("/", false);
        for (String child : children) {
            System.out.println(child);
        }
    }


    @Test
    


    public void testCreate() throws Exception {
        String conn = "192.168.154.10:2181,192.168.154.11:2181,192.168.154.12:2181";
        ZooKeeper zk = new ZooKeeper(conn, 5000, null);
        String s = zk.create("/a", "Tom".getBytes(StandardCharsets.UTF_8), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
        System.out.println(s);
        zk.close();
    }

    @Test
    

    public void testGet() throws Exception {
        String conn = "192.168.154.10:2181,192.168.154.11:2181,192.168.154.12:2181";
        ZooKeeper zk = new ZooKeeper(conn, 5000, null);
        Stat stat = new Stat();
        System.out.println(stat.toString());
        //获取接根节点的数据
        byte[] a = zk.getData("/a", false, stat);
        System.out.println(stat.toString());
        System.out.println(new String(a));
        zk.close();


    }

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

        new OperateZK().testList();
        //new OperateZK().testCreate();不要重复执行此命令,要重复执行此程序这一行记得注释掉。
        new OperateZK().testCreate();
        new OperateZK().testGet();
    }
}

cd /usr/local/src/zookeeper/bin

zkServer.sh start

启动zookeeper后就可以运行OperateZK.java了