SpringBoot 整合 Redisson——分布式锁最佳实践

自己用 Redis SETNX 实现的分布式锁有各种坑锁续期、误删、非原子。Redisson 是官方推荐的分布式锁方案开箱即用。一、引入依赖dependencygroupIdorg.redisson/groupIdartifactIdredisson-spring-boot-starter/artifactIdversion3.25.0/version/dependency二、配置ConfigurationpublicclassRedissonConfig{BeanpublicRedissonClientredissonClient(){ConfigconfignewConfig();config.useSingleServer().setAddress(redis://localhost:6379);returnRedisson.create(config);}}三、基础用法ServicepublicclassSeckillService{AutowiredprivateRedissonClientredissonClient;AutowiredprivateStringRedisTemplateredisTemplate;publicResultVO?seckill(LongproductId,LonguserId){StringlockKeylock:seckill:productId;RLocklockredissonClient.getLock(lockKey);// 尝试获取锁最多等3秒锁自动续期booleanlockedfalse;try{lockedlock.tryLock(3,30,TimeUnit.SECONDS);if(!locked){returnResultVO.error(429,操作太频繁请稍后重试);}// 业务逻辑returndoSeckill(productId,userId);}catch(InterruptedExceptione){returnResultVO.error(500,系统异常);}finally{// 释放锁只有持有锁的线程能释放if(lockedlock.isHeldByCurrentThread()){lock.unlock();}}}}四、注解式锁Target(ElementType.METHOD)Retention(RetentionPolicy.RUNTIME)publicinterfaceRedissonLock{/** 锁的key支持SpEL */Stringkey();/** 等待锁时间 */longwaitTime()default3;/** 锁过期时间 */longleaseTime()default30;}AspectComponentpublicclassRedissonLockAspect{AutowiredprivateRedissonClientredissonClient;Around(annotation(lock))publicObjectaround(ProceedingJoinPointpjp,RedissonLocklock)throwsThrowable{StringkeyparseKey(lock.key(),pjp);RLockrlockredissonClient.getLock(key);booleanlockedrlock.tryLock(lock.waitTime(),lock.leaseTime(),TimeUnit.SECONDS);if(!locked){thrownewBusinessException(429,操作太频繁);}try{returnpjp.proceed();}finally{if(rlock.isHeldByCurrentThread()){rlock.unlock();}}}}五、可重入锁// Redisson 的锁是可重入的// 同一个线程可以多次获取同一个锁publicvoidmethodA(){RLocklockredissonClient.getLock(lock:test);lock.lock();methodB();// 内部再次获取同一个锁不会死锁lock.unlock();}publicvoidmethodB(){RLocklockredissonClient.getLock(lock:test);lock.lock();// 业务逻辑lock.unlock();}六、公平锁// 公平锁按请求顺序获取锁RLockfairLockredissonClient.getFairLock(lock:fair);七、读写锁// 读锁多个线程可同时读// 写锁独占RReadWriteLockrwLockredissonClient.getReadWriteLock(lock:rw);RLockreadLockrwLock.readLock();// 读锁RLockwriteLockrwLock.writeLock();// 写锁八、Redisson vs 手写 SETNX特性手写 SETNXRedisson锁续期❌ 自己实现✅ 自动续期释放校验❌ 可能误删✅ 校验线程可重入❌✅公平锁❌✅读写锁❌✅看门狗❌✅九、看门狗机制// Redisson 的锁默认使用看门狗watchdog// 如果业务执行时间超过锁的过期时间默认30秒看门狗会自动续期// 每 10 秒续期一次直到业务完成释放锁// 注意只有不指定 leaseTime 时看门狗才生效RLocklockredissonClient.getLock(lock:test);lock.lock();// 不指定leaseTime → 看门狗生效十、秒杀场景最佳实践ServicepublicclassSeckillService{RedissonLock(keyseckill:#productId,waitTime3,leaseTime30)publicResultVO?doSeckill(PathVariableLongproductId,LonguserId){// 前置校验SeckillProductproductproductService.getById(productId);if(productnull||product.getStatus()!1){returnResultVO.error(404,商品不存在);}// 时间校验LocalDateTimenowLocalDateTime.now();if(now.isBefore(product.getSeckillStart())){returnResultVO.error(400,秒杀未开始);}// 库存扣减introwsproductMapper.decrementStock(productId);if(rows0){returnResultVO.error(400,库存不足);}// 创建订单returnResultVO.success(秒杀成功);}} 觉得有用的话点赞 关注【张老师技术栈】吧每周更新 Java/Python/MySQL 实战干货不让你白来。