RedisTemplate分布式锁

低版本RedisTemplate

@Configuration
@ConditionalOnBean(RedisTemplate.class)
@Slf4j
public class RedisLockUtil {

    private static final Long SUCCESS = 1L;

    @Autowired
    private RedisTemplate redisTemplate;

    /**
     * 加锁
     * @param lockKey   锁的key
     * @param value     锁的val
     * @param expireTime    超时时间(秒)
     * @return
     */
    public boolean Lock(String lockKey, String value, int expireTime) {
        try {
            String script = "if redis.call('setNx',KEYS[1],ARGV[1]) then if redis.call('get',KEYS[1])==ARGV[1] then return redis.call('expire',KEYS[1],ARGV[2]) else return 0 end end";
            RedisScript<String> redisScript = new DefaultRedisScript<>(script, String.class);
            Object result = redisTemplate.execute(redisScript, Collections.singletonList(lockKey), value, String.valueOf(expireTime));
            if (SUCCESS.equals(result)) {
                return true;
            }

        } catch (Exception e) {
            log.error("分布式锁加锁失败", e);
        }
        return false;
    }

    /**
     * 解锁
     * @param lockKey
     * @param value
     * @return
     */
    public boolean unLock(String lockKey, String value) {

        String script = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";
        RedisScript<String> redisScript = new DefaultRedisScript<>(script, String.class);
        Object result = redisTemplate.execute(redisScript, Collections.singletonList(lockKey), value);
        if (SUCCESS.equals(result)) {
            return true;
        }
        return false;
    }
}

高版本RedisTemplate

高版本中已封装了setIfAbsent(key, val, expreTime, unit)方法，可直接调用

@Configuration
public class RedisLock {

    private static final Long SUCCESS = 1L;

    @Autowired
    private RedisTemplate redisTemplate;

    /**
     * 加锁
     * @param key   锁的key
     * @param val   锁的val
     * @param timeOut   获取锁的超时时间
     * @param expreTime 锁过期时间
     * @param unit      过期单位
     * @return
     */
    public boolean tryLock(String key, String val, long timeOut,long expreTime,TimeUnit unit){
        long start = System.currentTimeMillis();
        for (;;) {
            Boolean aBoolean = redisTemplate.opsForValue().setIfAbsent(key, val, expreTime, unit);
            if (aBoolean){
                return true;
            }
            long time = System.currentTimeMillis() - start;
            if (time > timeOut){
                return false;
            }
        }
    }

    /**
     * 解锁
     * @param key
     * @param val
     * @return
     */
    public boolean unLock(String key, String val){
        String script = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";
        RedisScript<Long> redisScript = new DefaultRedisScript<>(script, Long.class);
        Object execute = redisTemplate.execute(redisScript, Collections.singletonList(key), val);
        if(SUCCESS.equals(execute)) {
            return true;
        }
        return false;
    }
}