ZooKeeper之Java客户端

Java操作Zookeeper很简单，但是前提要把包导对。

1.引入依赖

<?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">
<parent>
<artifactId>zookeeper-parent</artifactId>
<groupId>com.bruceliu.zookeeper</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>

<artifactId>zookeeper-client</artifactId>

<dependencies>
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.4.6</version>
</dependency>

<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>

</dependencies>


</project>

2.编写工具类代码

package com.bruceliu.utils;


import java.util.List;
import java.util.concurrent.CountDownLatch;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.Event.KeeperState;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.data.Stat;


/**
* @author bruceliu
* @create 2019-11-04 23:26
* @description
*/
public class BaseZookeeper implements Watcher{

private ZooKeeper zookeeper;
/**
* 超时时间
*/
private static final int SESSION_TIME_OUT = 2000;

public void process(WatchedEvent event) {
if (event.getState() == KeeperState.SyncConnected) {
System.out.println("Watch received event");
}
}


/**连接zookeeper
* @param host
* @throws Exception
*/
public void connectZookeeper(String host) throws Exception{
zookeeper = new ZooKeeper(host, SESSION_TIME_OUT, this);
System.out.println("zookeeper connection success");
}

/**
* 创建节点
* @param path
* @param data
* @throws Exception
*/
public String createNode(String path,String data) throws Exception{
return this.zookeeper.create(path, data.getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
}

/**
* 获取路径下所有子节点
* @param path
* @return
* @throws KeeperException
* @throws InterruptedException
*/
public List<String> getChildren(String path) throws KeeperException, InterruptedException{
List<String> children = zookeeper.getChildren(path, false);
return children;
}

/**
* 获取节点上面的数据
* @param path 路径
* @return
* @throws KeeperException
* @throws InterruptedException
*/
public String getData(String path) throws KeeperException, InterruptedException{
byte[] data = zookeeper.getData(path, false, null);
if (data == null) {
return "";
}
return new String(data);
}

/**
* 设置节点信息
* @param path 路径
* @param data 数据
* @return
* @throws KeeperException
* @throws InterruptedException
*/
public Stat setData(String path,String data) throws KeeperException, InterruptedException{
Stat stat = zookeeper.setData(path, data.getBytes(), -1);
return stat;
}

/**
* 删除节点
* @param path
* @throws InterruptedException
* @throws KeeperException
*/
public void deleteNode(String path) throws InterruptedException, KeeperException{
zookeeper.delete(path, -1);
}

/**
* 获取创建时间
* @param path
* @return
* @throws KeeperException
* @throws InterruptedException
*/
public String getCTime(String path) throws KeeperException, InterruptedException{
Stat stat = zookeeper.exists(path, false);
return String.valueOf(stat.getCtime());
}

/**
* 获取某个路径下孩子的数量
* @param path
* @return
* @throws KeeperException
* @throws InterruptedException
*/
public Integer getChildrenNum(String path) throws KeeperException, InterruptedException{
int childenNum = zookeeper.getChildren(path, false).size();
return childenNum;
}
/**
* 关闭连接
* @throws InterruptedException
*/
public void closeConnection() throws InterruptedException{
if (zookeeper != null) {
zookeeper.close();
}
}

public static void main(String[] args) throws Exception {
BaseZookeeper zookeeper = new BaseZookeeper();
zookeeper.connectZookeeper("192.168.126.128:2181");
List<String> children = zookeeper.getChildren("/");
System.out.println(children);
}
}

3.测试代码

package com.bruceliu.test;

import com.bruceliu.utils.BaseZookeeper;
import org.apache.zookeeper.KeeperException;
import org.junit.Before;
import org.junit.Test;

/**
* @author bruceliu
* @create 2019-11-04 23:28
* @description
*/
public class TestZookeeper {

BaseZookeeper baseZookeeper;

@Before
public void init(){
try {
baseZookeeper=new BaseZookeeper();
baseZookeeper.connectZookeeper("127.0.0.1:2181");
} catch (Exception e) {
e.printStackTrace();
} finally {
}
}

@Test
public void testCreateNode(){
try {
baseZookeeper.createNode("/testNode","test Data!");
} catch (Exception e) {
e.printStackTrace();
} finally {
}
}

@Test
public void testGetData(){
try {
String data = baseZookeeper.getData("/testNode");
System.out.println(data);
} catch (KeeperException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
}
}

}