Springboot整合zookeeper實(shí)現(xiàn)對(duì)節(jié)點(diǎn)的創(chuàng)建、監(jiān)聽與判斷的案例詳解

更新時(shí)間：2022年06月24日 09:46:53 作者：啊陳曉

這篇文章主要介紹了基于Springboot整合zookeeper實(shí)現(xiàn)對(duì)節(jié)點(diǎn)的創(chuàng)建、監(jiān)聽與判斷,本文通過實(shí)例代碼給大家介紹的非常詳細(xì)，對(duì)大家的學(xué)習(xí)或工作具有一定的參考借鑒價(jià)值，需要的朋友可以參考下

Springboot整合zookeeper教程

1.環(huán)境準(zhǔn)備

zookeeper集群環(huán)境
一個(gè)簡單的springboot項(xiàng)目環(huán)境

不懂如何搭建zookeeper集群的小伙伴可以移步到我的另一篇文章喔，里面有詳細(xì)的zookeeper集群搭建教程~

zookeeper集群搭建步驟（超詳細(xì)）

http://www.dbjr.com.cn/article/252826.htm

2.代碼編寫

2.1.在pom.xml文件中增加zookeeper依賴（記得跟自己的zookeeper版本對(duì)應(yīng)）

除此之外，我們也引入junit和log4j方便我們后面的測試

   <!--引入對(duì)應(yīng)的zookeeper -->
        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <version>3.7.1</version>
        </dependency>
 
   <!--引入日志-->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-to-slf4j</artifactId>
            <version>2.17.2</version>
        </dependency>
 
   <!--引入junit測試-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>RELEASE</version>
        </dependency>

2.2.API測試

我們創(chuàng)建zkClient類用于實(shí)現(xiàn)對(duì)zookeeper中節(jié)點(diǎn)的操作：

1.客戶端初始化

package com.canrioyuan.zookeepertest;
 
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;
 
//創(chuàng)建對(duì)應(yīng)的zookeeper客戶端
public class ZkClient {
 
    //對(duì)應(yīng)的zookeeper客戶端連接,連接之間不能存在空格
    private String connectString = "192.168.154.133:2181,192.168.154.134:2181,192.168.154.135:2181";
    //即超時(shí)時(shí)間，我們設(shè)置成2s
    private int sessionTimeout = 2000;
    //聲明zookeeper客戶端
    private ZooKeeper zkClient;

    //初始化
    @Test
    public void init() throws IOException {
        zkClient = new ZooKeeper(connectString, sessionTimeout, new Watcher() {
            @Override
            public void process(WatchedEvent watchedEvent) {
 
            }
        });
    }
 
}

運(yùn)行測試，成功后如會(huì)出現(xiàn)下圖所示結(jié)果：

2.創(chuàng)建節(jié)點(diǎn)

    //創(chuàng)建節(jié)點(diǎn)
    @Test
    public void create() throws InterruptedException, KeeperException {
        //public String create(String path, byte[] data, List<ACL> acl, CreateMode createMode)
        //上圖中從左到右的參數(shù)分別對(duì)應(yīng)著：你所要?jiǎng)?chuàng)建的節(jié)點(diǎn)的名字，節(jié)點(diǎn)的值，節(jié)點(diǎn)的權(quán)限，節(jié)點(diǎn)的類型（持久有序，持久無序，臨時(shí)有序，臨時(shí)無序）
        zkClient.create("/class", "LiHua".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
    }

運(yùn)行測試，你會(huì)發(fā)現(xiàn)，程序報(bào)了這樣的錯(cuò)誤;

這是因?yàn)槲覀儨y試方法是互相獨(dú)立的，此時(shí)運(yùn)行測試，客戶端處于未初始化的狀態(tài)。因此，我們在客戶端類的init方法中將@Test注解改成@Before注解，表示在每個(gè)測試執(zhí)行之前都必須執(zhí)行初始化方法。

  //初始化
    @Before
//    @Test
    public void init() throws IOException {
        zkClient = new ZooKeeper(connectString, sessionTimeout, new Watcher() {
            @Override
            public void process(WatchedEvent watchedEvent) {
 
            }
        });
    }

這時(shí)候我們再運(yùn)行，會(huì)提示運(yùn)行成功

我們來到任意一臺(tái)zookeeper客戶端中查看節(jié)點(diǎn)，會(huì)發(fā)現(xiàn)已經(jīng)創(chuàng)建成功

3.監(jiān)聽節(jié)點(diǎn)的狀態(tài)

一次監(jiān)聽只能生效一次，而為了能夠持續(xù)監(jiān)聽，我們對(duì)初始化方法再做出調(diào)整，保證每次初始化都有一次監(jiān)聽生效。

 @Before
    public void init() throws IOException {
        zkClient = new ZooKeeper(connectString, sessionTimeout, new Watcher() {
            @Override   //process中即為監(jiān)聽后做出的處理
            public void process(WatchedEvent watchedEvent) {
                List<String> children = null;
                try {
                    children = zkClient.getChildren("/", true);
                } catch (KeeperException e) {
                    e.printStackTrace();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println("-------------------------");
                for (String child : children) {
                    System.out.println(child);
                }
                System.out.println("-------------------------");
 
            }
        });
    }

然后在監(jiān)聽節(jié)點(diǎn)代碼中進(jìn)行延時(shí)操作

 //監(jiān)聽節(jié)點(diǎn)
    @Test
    public void getChildren() throws InterruptedException, KeeperException {
 
        //正常一次監(jiān)聽只會(huì)生效一次，因此我們設(shè)置延時(shí)監(jiān)聽，確保能夠持續(xù)監(jiān)聽節(jié)點(diǎn)的變化。
        Thread.sleep(Long.MAX_VALUE);
    }

此時(shí)我們可以看到控制臺(tái)輸出了zookeeper中的節(jié)點(diǎn)：

我們進(jìn)入zookeeper客戶端對(duì)節(jié)點(diǎn)進(jìn)行操作

增加一個(gè)節(jié)點(diǎn)school

返回控制臺(tái)，此時(shí)已經(jīng)監(jiān)聽到了節(jié)點(diǎn)的變化：

我們再對(duì)school這個(gè)節(jié)點(diǎn)進(jìn)行刪除操作

此時(shí)控制臺(tái)同樣監(jiān)聽到了節(jié)點(diǎn)的變化：

4.判斷節(jié)點(diǎn)是否存在

 //判斷節(jié)點(diǎn)是否存在
    @Test
    public void status() throws InterruptedException, KeeperException {
        Stat status = zkClient.exists("/class", false);
        System.out.println(status == null ? "no exist" : "exist");
    }

此時(shí)zookeeper中的節(jié)點(diǎn);

測試結(jié)果：

3.全部代碼

package com.canrioyuan.zookeepertest;
 
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;
 
//創(chuàng)建對(duì)應(yīng)的zookeeper客戶端
public class ZkClient {
 
    //對(duì)應(yīng)的zookeeper客戶端連接,連接之間不能存在空格
    private String connectString = "192.168.154.133:2181,192.168.154.134:2181,192.168.154.135:2181";
    //即超時(shí)時(shí)間，我們設(shè)置成2s
    private int sessionTimeout = 2000;
    //聲明zookeeper客戶端
    private ZooKeeper zkClient;

    //初始化
//    @Test
    @Before
    public void init() throws IOException {
        zkClient = new ZooKeeper(connectString, sessionTimeout, new Watcher() {
            @Override   //process中即為監(jiān)聽后做出的處理
            public void process(WatchedEvent watchedEvent) {
                List<String> children = null;
                try {
                    children = zkClient.getChildren("/", true);
                } catch (KeeperException e) {
                    e.printStackTrace();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println("-------------------------");
                for (String child : children) {
                    System.out.println(child);
                }
                System.out.println("-------------------------");
 
            }
        });
    }
 
    //創(chuàng)建節(jié)點(diǎn)
    @Test
    public void create() throws InterruptedException, KeeperException {
        //public String create(String path, byte[] data, List<ACL> acl, CreateMode createMode)
        //上圖中從左到右的參數(shù)分別對(duì)應(yīng)著：你所要?jiǎng)?chuàng)建的節(jié)點(diǎn)的名字，節(jié)點(diǎn)的值，節(jié)點(diǎn)的權(quán)限，節(jié)點(diǎn)的類型（持久有序，持久無序，臨時(shí)有序，臨時(shí)無序）
        zkClient.create("/class", "LiHua".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
    }
 
    //監(jiān)聽節(jié)點(diǎn)
    @Test
    public void getChildren() throws InterruptedException, KeeperException {
 
        //正常一次監(jiān)聽只會(huì)生效一次，因此我們設(shè)置延時(shí)監(jiān)聽，確保能夠持續(xù)監(jiān)聽節(jié)點(diǎn)的變化。
        Thread.sleep(Long.MAX_VALUE);
    }
 
    //判斷節(jié)點(diǎn)是否存在
    @Test
    public void status() throws InterruptedException, KeeperException {
        Stat status = zkClient.exists("/class", false);
        System.out.println(status == null ? "no exist" : "exist");
    }
}

至此，我們基于Springboot整合zookeeper實(shí)現(xiàn)對(duì)節(jié)點(diǎn)的創(chuàng)建、監(jiān)聽與判斷教程就結(jié)束啦~

到此這篇關(guān)于基于Springboot整合zookeeper實(shí)現(xiàn)對(duì)節(jié)點(diǎn)的創(chuàng)建、監(jiān)聽與判斷的文章就介紹到這了,更多相關(guān)Springboot整合zookeeper實(shí)現(xiàn)節(jié)點(diǎn)監(jiān)聽內(nèi)容請(qǐng)搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！

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