缓存穿透.txt

【文件属性】：

文件名称：缓存穿透.txt

文件大小：860B

文件格式：TXT

更新时间：2022-09-12 03:38:21

高并发技术

@Service("userServiceImpl") public class UserServiceImpl implements UserService { @Autowired private UserMapper userMapper; @Autowired private RedisTemplate<Object,Object> redisTemplate; @Override public Long queryAllUserCount() { Long allUserCount= (Long) redisTemplate.opsForValue().get(Constants.ALL_USER_COUNT); if(allUserCount==null){ //注意缓存穿透 synchronized (this){ allUserCount= (Long) redisTemplate.opsForValue().get(Constants.ALL_USER_COUNT); if(allUserCount==null){ allUserCount=userMapper.selectAllUserCount(); redisTemplate.opsForValue().set(Constants.ALL_USER_COUNT, allUserCount, 15, TimeUnit.SECONDS); } } } return allUserCount; } }