下面是一个简单的Java代码示例,演示如何使用Redis的tryLock方法实现分布式锁: Jedisjedis=newJedis("localhost");StringlockKey="myLock";StringrequestId=UUID.randomUUID().toString();intexpireTime=60;// 锁的过期时间,单位秒// 尝试获取锁Booleanlocked=jedis.set(lockKey,requestId,"NX","EX",expireTime);if...
"local counter = redis.call('hincrby', KEYS[1], ARGV[3], -1); " + //走到这,确定当前线程持有锁, 对锁减一, (可重入) "if (counter > 0) then " + // 如果还持有锁, 没释放完 "redis.call('pexpire', KEYS[1], ARGV[2]); " + //续期, 延长锁的时间到internalLockLeaseTime "retu...
就按照普通的方式获取锁if(leaseTime!=-1){returntryLockInnerAsync(leaseTime,unit,threadId,RedisCommands.EVAL_LONG);}//否则,在获取锁之后,需要加上定时任务,给锁设置一个内部过期时间,并不断刷新这个时间直到释放锁RFuture ttlRemainingFuture=tryLockInnerAsync(commandExecutor.getConnectionManager...
stringRedisTemplate);//获取锁对象booleanisLock = redisLock.tryLock(120);//加锁失败,说明当前用户开了多个线程抢优惠券,但是由于key是SETNX的,所以不能创建key,得等key的TTL到期或释放锁(删除key)if(!isLock) {returnResult.fail("不允许抢多张优惠券"); ...
基于Redis实现分布式锁 Redis是一个高性能的内存数据库,支持分布式锁的实现。基于Redis实现分布式锁的步骤如下: (1)获取Redis连接 (2)使用setnx命令设置键值对,如果返回值为1,则表示获取锁成功,否则获取锁失败 (3)如果获取锁失败,则使用get命令获取锁的值,并判断当前时间是否大于锁的超时时间,如果是,则使用getset...
// 通过分布式锁实现一人一单线程安全问题SimpleRedisLocklock=newSimpleRedisLock("order:"+ userId, stringRedisTemplate);// 获取锁boolean isLock =lock.tryLock(100);// 判断释放获取锁成功if(!isLock){// 获取锁失败,返回错误信息,或者重试returnResult.fail("不允许重复下单"); ...
tryAcquire 内部依靠 tryLockInnerAsync 来实现获取锁的逻辑,我们来看下源码 <T> RFuture<T> tryLockInnerAsync(long leaseTime, TimeUnit unit, long threadId, RedisStrictCommand<T> command) { internalLockLeaseTime = unit.toMillis(leaseTime); return commandExecutor.evalWriteAsync(getName(), LongCodec.INSTA...
public boolean tryLock() { return tryLock(LockRedisConst.DEFAULT_KEY); } @Override public void unlock() { unlock(LockRedisConst.DEFAULT_KEY); } @Override public boolean tryLock(long time, TimeUnit unit, String key) throws InterruptedException { ...
boolean tryLock(String key, String requestId, long timeout, TimeUnit unit); boolean releaseLock(String key, String requestId); } public class RedisDistributedLock implements DistributedLock { private final RedisTemplate<String, String> redisTemplate; ...