ZooKeeper总结学习 第四课 -java API应用

4.3.1 idea环境搭建

1．创建一个Maven工程

2．添加pom文件

<dependencies>      <dependency>          <groupId>junit</groupId>          <artifactId>junit</artifactId>          <version>RELEASE</version>      </dependency>      <dependency>          <groupId>org.apache.logging.log4j</groupId>          <artifactId>log4j-core</artifactId>          <version>2.8.2</version>      </dependency>      <!-- https://mvnrepository.com/artifact/org.apache.zookeeper/zookeeper -->      <dependency>          <groupId>org.apache.zookeeper</groupId>          <artifactId>zookeeper</artifactId>          <version>3.4.10</version>      </dependency> </dependencies>

 

3．拷贝log4j.properties文件到项目根目录

   需要在项目的src/main/resources目录下，新建一个文件，命名为“log4j.properties”，在文件中填入。

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  

4.3.2 创建ZooKeeper客户端

package com.dukun.study;

import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooKeeper;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringZkStudyApplicationTests {


	private static String connectString = "127.0.0.1:2181,127.0.0.1:2182,127.0.0.1:2183";
	private static int sessionTimeout = 2000;
	private ZooKeeper zkClient = null;

	/**
	 *  创建zk连接客户端
	 * @throws Exception
	 */
	@Test
	public void init() throws Exception{
		//创建zk连接客户端
		zkClient=new ZooKeeper(connectString, sessionTimeout, new Watcher() {
			@Override
			public void process(WatchedEvent watchedEvent) {

			}
		});
	}

}

4.3.3 创建子节点

/**
	 * 创建节点
	 * @throws Exception
	 */
	@Test
	public void create() throws Exception {
		// 参数1：要创建的节点的路径； 参数2：节点数据 ； 参数3：节点权限 ；参数4：节点的类型
		String nodeCreated =	zkClient.create("/dukun","ceshishiyong".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
		System.out.println("创建节点:"+nodeCreated);
	}

 

4.3.4 获取节点中数据

	// 获取节点中 数据
	@Test
	public void getNodeDat() throws Exception {
		//要先获取节点相关信息 不加监听 然后在获取数据
	  Stat stat= zkClient.exists("/dukun",false);
		byte[] data =zkClient.getData("/dukun",false,stat);
	    String dataSt= new String(data);
		System.out.println(data);
	}

4.3.5 获取子节点并监听节点变化

  通过监听获取节点中的变化  process（）

new Watcher() {
   @Override
   public void process(WatchedEvent watchedEvent) {

   }
}

/**
	 *  创建zk连接客户端
	 * @throws Exception
	 */
	@Before
	public void init() throws Exception{
		//创建zk连接客户端
		zkClient=new ZooKeeper(connectString, sessionTimeout, new Watcher() {
			@Override
			public void process(WatchedEvent watchedEvent) {
				// 收到事件通知后的回调函数（用户的业务逻辑）
				System.out.println(watchedEvent.getType() + "--" + watchedEvent.getPath());
				// 再次启动监听
				try {
					zkClient.getChildren("/", true);
				} catch (Exception e) {
					e.printStackTrace();
				}

			}
		});
	}

	// 获取子节点
	@Test
	public void getChildren() throws Exception {

		//获取节点信息并加监听
		List<String> children = zkClient.getChildren("/", true);

		for (String child : children) {
			System.out.println(child);
		}
		// 延时阻塞
		Thread.sleep(Long.MAX_VALUE);
	}