Java基于ZooKeeper接口对zk节点数据进行增删改查操作

Java基于ZooKeeper接口对zk节点数据进行增删改查操作

详情请看代码注释

一、准备条件

• 安装好zk的机器（ip:192.168.10.201）
• 启动zkServer：bin/zkServer.sh localhost:2181 start

二、创建项目，编写代码

1、引入maven

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>top.it1002</groupId>
    <artifactId>ZooKeeperDemo</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <version>3.4.13</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
    </dependencies>
    
</project>

2、代码实现

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.util.ArrayList;

/**
 * @Author  :王磊
 * @Date    ：2019/3/29
 * @Desc    ：zookeeper节点的增删改查操作
 */

public class ZooKeeperCURDTest {
     
    /**
     * 迭代获取父节点的子节点
     * @param parentNodeName
     * @param zooKeeper
     * @return
     */
    public ArrayList<String> iterChildNodeList(String parentNodeName, ZooKeeper zooKeeper){
     
        if(parentNodeName != null && !parentNodeName.equals("")){
     
            try {
     
                ArrayList<String> childNodeList = (ArrayList<String>)zooKeeper.getChildren(parentNodeName, null);
                if(childNodeList.size() > 0){
     
                    System.out.println("父结点:" + parentNodeName);
                    for(String childNode : childNodeList){
     
                        String childNodePath = "";
                        if(!parentNodeName.equals("/")){
     
                            childNodePath = parentNodeName + "/" + childNode;
                        }else {
     
                            childNodePath = parentNodeName +  childNode;
                        }
                        System.out.println(parentNodeName + "的子节点：" + childNodePath);
                        iterChildNodeList(childNodePath, zooKeeper);
                    }
                }
            } catch (Exception e) {
     
                e.printStackTrace();
            }
        }
        return new ArrayList<String>();
    }

    /**
     * 获取服务器节点列表
     */
    @Test
    public void listTest(){
     
        try {
     
            ZooKeeper zooKeeper = new ZooKeeper("192.168.10.201:2181", 10000, null);
            String root = "/";
            iterChildNodeList(root, zooKeeper);
        } catch (Exception e) {
     
            e.printStackTrace();
        }
    }

    /**
     * 获取指定节点的节点数据
     */
    @Test
    public void getDataTest(){
     
        try {
     
            ZooKeeper zooKeeper = new ZooKeeper("192.168.10.201:2181", 10000, null);
            String path = "/it1002";
            String data = new String(zooKeeper.getData(path, null, new Stat()));
            System.out.println(data);
        } catch (Exception e) {
     
            e.printStackTrace();
        }
    }

    /**
     * 节点创建测试
     */
    @Test
    public void createTest(){
     
        try{
     
            ZooKeeper zooKeeper = new ZooKeeper("192.168.10.201:2181", 10000,null);
            String dataStr = "100";
            byte[] data = dataStr.getBytes();
            // CreateMode:
            //（1）PERSISTENT：持久；（2）PERSISTENT_SEQUENTIAL：持久顺序；（3）EPHEMERAL：临时；（4）EPHEMERAL_SEQUENTIAL：临时顺序。
            String res = zooKeeper.create("/it1002/grade", data, ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
            if(res != null && !res.equals("")){
     
                System.out.println("插入节点为：" + res);
                String newData = new String(zooKeeper.getData("/it1002/grade", null, new Stat()));
                System.out.println("新插入数据为:" + newData);
            }else {
     
                System.out.println("创建失败！");
            }
        }catch (Exception e){
     
            System.out.println(e);
        }
    }

    /**
     * 节点数据更新测试
     */
    @Test
    public void setTest(){
     
        try{
     
            ZooKeeper zooKeeper = new ZooKeeper("192.168.10.201:2181", 10000,null);
            // 修改的节点
            String path = "/it1002/sex";
            // 修改的新数据
            byte[] data = new String("man").getBytes();
            // 期望更新的版本号
            // 从未修改后的话版本号为0，修改成功后版本号递增1
            int version = 0;
            // 修改之前的节点数据
            String beforeData = new String(zooKeeper.getData(path, null, new Stat()));
            Stat stat = zooKeeper.setData(path, data, version);
            // 修改之后的版本号
            int newVersion = stat.getVersion();
            // 修改之后的节点数据
            String afterData = new String(zooKeeper.getData(path, null, new Stat()));
            System.out.println("更新之前数据为:" + beforeData);
            System.out.println("更新之后数据为:" + afterData);
            System.out.println("更新数据后新版本号为:" + newVersion);
        }catch (Exception e){
     
            System.out.println(e);
        }
    }

    /**
     * 节点删除测试
     */
    @Test
    public void deleteTest(){
     
        try{
     
            ZooKeeper zooKeeper = new ZooKeeper("192.168.10.201:2181", 10000,null);
            // 删除的节点
            String path = "/it1002/grade";
            Stat stat = zooKeeper.exists(path, null);
            // 删除的节点的版本
            int version = stat.getVersion();
            // 执行删除
            zooKeeper.delete(path, version);
            // 删除后列出最新的zk节点结构
            listTest();
        }catch (Exception e){
     
            System.out.println(e);
        }
    }
}

后续会持续更新大数据组件相关demo，欢迎私信讨论