zookeeper分布式锁

 首先引入jar包

 
        
            org.apache.curator
            curator-recipes
            2.7.0
            
                
                    com.google.guava
                    guava
                
            
        

Curator提供了InterProcessMutex类帮助我们实现分布式锁，内部是实现了临时顺序节点（EPHEMERAL_SEQUENTIAL）

单线程下使用方法 ： 

        //加入zk锁
        CuratorFramework client = CuratorFrameworkFactory.newClient(“127.0.0.1:2181”,
                new ExponentialBackoffRetry(1000, 3));
        client.start();

        String lockpath="/temp";
        InterProcessMutex lock = new InterProcessMutex(client, lockpath);

        try {

            //加锁成功
            if (lock.acquire(3, TimeUnit.SECONDS)) {

                System.out.println("加锁成功");

            }else{
                System.out.println("加锁失败");
            }

        } catch (Exception e) {
            System.out.println("加锁失败");
        } finally {
            try {
                lock.release();
            } catch (Exception e) {
                
            }
            CloseableUtils.closeQuietly(client);

        }

多线程下使用方法：

public static void main(String args[]) throws Exception {

        RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3);
        CuratorFramework client = CuratorFrameworkFactory.newClient("127.0.0.1:2181", retryPolicy);
        client.start();


        ExecutorService fixedThreadPool = Executors.newFixedThreadPool(5);

        for (int i = 0; i < 5; i++) {
            fixedThreadPool.submit(new Runnable() {

                @Override
                public void run() {

                    try {

                        InterProcessMutex ipm = new InterProcessMutex(client, "/zktest");
                        try {
                            ipm.acquire();

                            System.out.println("Thread ID:" + Thread.currentThread().getId() + " acquire the lock");

                            Thread.sleep(1000);

                            System.out.println("Thread ID:" + Thread.currentThread().getId() + " release the lock");
                        } catch (Exception e) {

                        } finally {
                            ipm.release();
                        }



                    } catch (Exception e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }

                }
            });
        }
    }