分布式锁

Posted 2021-03-05 z360519549

一： 使用redis：

    @PostMapping("/v1/getLock2")
    public  BaseResponse  getLock2(@RequestBody GxyTeacherInfoDto dto) throws  Exception{
        String key = "product_001";
        String lockvalue = UUID.randomUUID().toString();
        Boolean bool = stringRedisTemplate.opsForValue().setIfAbsent(key,lockvalue,10,TimeUnit.SECONDS);
        if(!bool) {
            System.out.println("err");
            return BaseResponse.error();
        }
        try {
            int stock = Integer.parseInt(stringRedisTemplate.opsForValue().get("stock"));
            if (stock > 0) {
                int realStock = stock - 1;
                stringRedisTemplate.opsForValue().set("stock",realStock+"");
                System.out.println("售卖成功，剩余" + realStock);
                return BaseResponse.ok();
            } else {
                System.out.println("err2");
                return BaseResponse.error();
            }
        } finally {
            if(lockvalue.equals(stringRedisTemplate.opsForValue().get(key))) {
                stringRedisTemplate.delete(key);
            }
        }


    }

二： 使用Redisson:

@Bean
public Redisson redisson(){
    Config config = new Config();
    config.useSingleServer().setAddress("redis://IP:port");
    return (Redisson)Redisson.create(config);
}

    @PostMapping("/v1/getLock3")
    public  BaseResponse  getLock3(@RequestBody GxyTeacherInfoDto dto) throws  Exception{
        String lockKey = "product_001";
        RLock redissonLock = redisson.getLock(lockKey);
        try {
            int stock = Integer.parseInt(stringRedisTemplate.opsForValue().get("stock"));
            if (stock > 0) {
                int realStock = stock - 1;
                stringRedisTemplate.opsForValue().set("stock",realStock+"");
                System.out.println("售卖成功，剩余" + realStock);
                return BaseResponse.ok();
            } else {
                System.out.println("err2");
                return BaseResponse.error();
            }
        } finally {
            redissonLock.unlock();
        }
    }