ZooKeeper（八）-- Curator实现分布式锁

1.pom.xml

  <dependencies>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.10</version>
        <scope>test</scope>
   </dependency>
   <dependency>
        <groupId>org.apache.zookeeper</groupId>
        <artifactId>zookeeper</artifactId>
        <version>3.4.6</version>
   </dependency>
   <dependency>
       <groupId>org.apache.curator</groupId>
       <artifactId>curator-recipes</artifactId>
       <version>2.5.0</version>
   </dependency>
  </dependencies>

2.JAVA代码

 package com.xbq.zookeeper.curator;

 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.TimeUnit;
 import org.apache.curator.framework.CuratorFramework;
 import org.apache.curator.framework.CuratorFrameworkFactory;
 import org.apache.curator.framework.recipes.locks.InterProcessMutex;
 import org.apache.curator.retry.RetryNTimes;

 /**
  * 使用Curator来实现分布式锁
  * @author xbq
  */
 public class LockByCurator {

     // 此demo使用的集群，所以有多个ip和端口
     private static String CONNECT_SERVER = "192.168.242.129:2181,192.168.242.129:2182,192.168.242.129:2183";
     // session过期时间
     private static int SESSION_TIMEOUT = 3000;
     // 连接超时时间
     private static int CONNECTION_TIMEOUT = 3000; 

     // 锁节点
     private static final String CURATOR_LOCK = "/curatorLock";

     /**
      * 获取锁操作
      * @param cf
      */
     public static void doLock(CuratorFramework cf){
         System.out.println(Thread.currentThread().getName() + " 尝试获取锁！");
         // 实例化 zk分布式锁
         InterProcessMutex mutex = new InterProcessMutex(cf, CURATOR_LOCK);
         try {
             // 判断是否获取到了zk分布式锁
             if(mutex.acquire(5, TimeUnit.SECONDS)){
                 System.out.println(Thread.currentThread().getName() + " 获取到了锁！-------");
                 // 业务操作
                 Thread.sleep(5000);
             }
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             try {
                 // 释放锁
                 mutex.release();
             } catch (Exception e) {
                 e.printStackTrace();
             }
         }
     }

     /**
      * 测试
      * @param args
      */
     public static void main(String[] args) {
         // 定义线程池
         ExecutorService service = Executors.newCachedThreadPool();
         // 定义信号灯，只能允许10个线程并发操作
         final Semaphore semaphore = new Semaphore(10);
         // 模拟10个客户端
         for(int i=0; i < 10 ;i++){
             Runnable runnable = new Runnable() {
                 @Override
                 public void run() {
                     try {
                         semaphore.acquire();
                          // 连接 ZooKeeper
                         CuratorFramework framework = CuratorFrameworkFactory.
                                 newClient(CONNECT_SERVER, SESSION_TIMEOUT, CONNECTION_TIMEOUT, new RetryNTimes(10,5000));
                         // 启动
                         framework.start();
                         doLock(framework);

                         semaphore.release();
                     } catch (Exception e) {

                     }
                 }
             };
             service.execute(runnable);
         }
         service.shutdown();
     }
 }