高并发下redis缓存穿透问题解决

try{
 
            //序列化器，将key的值设置为字符串
            RedisSerializer redisSerializer=new StringRedisSerializer();
            redisTemplate.setKeySerializer(redisSerializer);
 
            //查缓存
            List list=(List)redisTemplate.opsForValue().get("allUsers");
 
            if(null==list){
                //双重检测 锁
                synchronized (this) {
 
                    List list1 = (List) redisTemplate.opsForValue().get("allUsers");
                    if (null == list1) {
 
                        UsersQuery query=new UsersQuery();
                        list=usersDOMapper.selectByExample(query);
                        redisTemplate.opsForValue().set("allUsers", list);
 
                        System.out.println("从数据库中取数据");
                    }
                    else{
                        System.out.println("从缓存中取数据");
                    }
                }
            }
            else{
                System.out.println("从缓存中取数据");
            }
            return list;
        }
        catch (Exception e) {
            logger.error("UserService.getAllUserWithNoPage error",e);
        }

ExecutorService executorService= Executors.newFixedThreadPool(20);
 
        for(int i=1 ; i<=10000;i++){
 
            executorService.submit(new Runnable() {
                @Override
                public void run() {
                    userService.getAllUserWithNoPage();
                }
            });
        }

从数据库中去数据

从缓存中取数据

从缓存中取数据

从缓存中取数据

从缓存中取数据

…