分布式锁之redisson

redisson是redis官网推荐的java语言实现分布式锁的项目。当然，redisson远不止分布式锁，还包括其他一些分布式结构。详情请移步：https://github.com/mrniko/redisson/wiki

　　redisson支持4种链接redis的方式：

　　Cluster(集群)

　　Sentinel servers(哨兵)

　　Master/Slave servers(主从)

　　Single server(单机)

　　下面通过简单的案例使用redisson的lock。

　　1、RedissonManager类，管理redisson的初始化等操作。

public class RedissonManager {

    private static final String RAtomicName = "genId_";

    private static Config config = new Config();
    private static Redisson redisson = null;

    public static void init(){
        try {
            config.useClusterServers() //这是用的集群server
                    .setScanInterval(2000) //设置集群状态扫描时间
                    .setMasterConnectionPoolSize(10000) //设置连接数
                    .setSlaveConnectionPoolSize(10000)
                    .addNodeAddress("127.0.0.1:6379","127.0.0.1:6380");
            redisson = Redisson.create(config);
            //清空自增的ID数字
            RAtomicLong atomicLong = redisson.getAtomicLong(RAtomicName);
            atomicLong.set(1);
        }catch (Exception e){
            e.printStackTrace();
        }
    }

    public static Redisson getRedisson(){
        return redisson;
    }

    /** 获取redis中的原子ID */
    public static Long nextID(){
        RAtomicLong atomicLong = getRedisson().getAtomicLong(RAtomicName);
        atomicLong.incrementAndGet();
        return atomicLong.get();
    }
}

　　2、DistributedRedisLock类，提供锁和解锁方法

public class DistributedRedisLock {
    private static Redisson redisson = RedissonManager.getRedisson();
    private static final String LOCK_TITLE = "redisLock_";

    public static void acquire(String lockName){
        String key = LOCK_TITLE + lockName;
        RLock mylock = redisson.getLock(key);
        mylock.lock(2, TimeUnit.MINUTES); //lock提供带timeout参数，timeout结束强制解锁，防止死锁
        System.err.println("======lock======"+Thread.currentThread().getName());
    }

    public static void release(String lockName){
        String key = LOCK_TITLE + lockName;
        RLock mylock = redisson.getLock(key);
        mylock.unlock();
        System.err.println("======unlock======"+Thread.currentThread().getName());
    }
}

3、测试

private static void redisLock(){
        RedissonManager.init(); //初始化
        for (int i = 0; i < 100; i++) {
            Thread t = new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        String key = "test123";
                        DistributedRedisLock.acquire(key);
                        Thread.sleep(1000); //获得锁之后可以进行相应的处理
                        System.err.println("======获得锁后进行相应的操作======");
                        DistributedRedisLock.release(key);
                        System.err.println("=============================");
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            });
            t.start();
        }
    }

4、测试结果

======lock======Thread-91
======获得锁后进行相应的操作======
======unlock======Thread-91
=============================
======lock======Thread-63
======获得锁后进行相应的操作======
======unlock======Thread-63
=============================
======lock======Thread-31
======获得锁后进行相应的操作======
======unlock======Thread-31
=============================
======lock======Thread-97
======获得锁后进行相应的操作======
======unlock======Thread-97
=============================
======lock======Thread-8
======获得锁后进行相应的操作======
======unlock======Thread-8
=============================