redis分布式锁的原理及代码实例

import redis.clients.jedis.Jedis;

public class RedisLock {

    private Jedis jedis;

    public RedisLock(String host, int port) {
        this.jedis = new Jedis(host, port);
    }

    //关闭Jedis客户端连接
    public void close() {
        jedis.close();
    }
}

public boolean lock(String lockKey, String requestId, int expireTime) {
    String result = jedis.set(lockKey, requestId, "NX", "PX", expireTime);
    if ("OK".equals(result)) {
        return true;
    }
    return false;
}

public boolean unlock(String lockKey, String requestId) {
    String lockValue = jedis.get(lockKey);
    if (requestId.equals(lockValue)) {
        jedis.del(lockKey);
        return true;
    }
    return false;
}

public void testLock(String lockKey) {
    String requestId = UUID.randomUUID().toString();
    RedisLock redisLock = new RedisLock("localhost", 6379);
    try {
        boolean lock = redisLock.lock(lockKey, requestId, 3000);
        if (lock) {
            System.out.println("获取锁成功");
            //模拟业务处理
            Thread.sleep(2000);
        } else {
            System.out.println("获取锁失败");
        }
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        boolean unlock = redisLock.unlock(lockKey, requestId);
        if (unlock) {
            System.out.println("释放锁成功");
        } else {
            System.out.println("释放锁失败");
        }
        redisLock.close();
    }
}