springcloud redis 缓存使用注意事项

注意事项

1、@cacheput vs @cacheable 注解选择的问题

查看文章： @cacheput VS @cacheable: https://blog.csdn.net/Prepared/article/details/82699056

简单来说就是 update 的时候应该用 cacheput

2、同一个redis key的方法应该形成闭环。

就是说同一个 key 的方法，增删改查都应该添加缓存，当然查询不是必须的，但是加入缓存不就是为了查询更快嘛。

示例

import com.baomidou.mybatisplus.mapper.EntityWrapper;
import com.baomidou.mybatisplus.mapper.SqlHelper;
import com.baomidou.mybatisplus.mapper.Wrapper;
import com.baomidou.mybatisplus.plugins.Page;
import com.baomidou.mybatisplus.service.impl.ServiceImpl;
import org.apache.log4j.Logger;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.CachePut;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

/**
 * <p>
 * 用户表 服务实现类
 * </p>
 *
 */
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {

    private static final org.apache.log4j.Logger logger = Logger.getLogger(UserServiceImpl.class);
    

    /**
     * 找用户列表
     *
     * @param page    分页对象
     * @param wrapper 条件
     * @return 用户列表
     */
    @Override
    public Page<UserObject> selectUser(Page<UserObject> page, Wrapper<UserObject> wrapper) {
        baseMapper.selectUser(page, wrapper);
        return page;
    }
    /**根据登录名返回用户对象*/
    @Override
    public UserObject selectUserWithExtByLoginName(String policeNo) {
        UserObject userObject = baseMapper.selectUserWithExtByLoginName(policeNo);
        return userObject;
    }

    @Transactional(rollbackFor = Exception.class)
    @Cacheable(value = CacheConstant.CACHE_PERSON_PREFIX, key="#user.userid")
    @Override
    public User insertObject(User user){
        baseMapper.insert(user);
        return user;
    }

    @CachePut(value = CacheConstant.CACHE_PERSON_PREFIX, key="#user.userid")
    @Transactional(rollbackFor = Exception.class)
    @Override
    public User update(User user) {
        baseMapper.updateById(user);
        return user;
    }

    @Transactional(rollbackFor = Exception.class)
    @Override
    @CacheEvict(value = CacheConstant.CACHE_PERSON_PREFIX, key="#user.userid")
    public boolean deleteById(User user) {
        return SqlHelper.delBool(baseMapper.deleteById(user.getUserid()));
    }

    @Transactional(rollbackFor = Exception.class)
    @Override
    @CacheEvict(value = CacheConstant.CACHE_PERSON_PREFIX)
    public boolean deleteBatchIds(List<String> idList) {
        return SqlHelper.delBool(baseMapper.deleteBatchIds(idList));
    }

    @Transactional(rollbackFor = Exception.class)
    @Override
    @CachePut(value = CacheConstant.CACHE_PERSON_PREFIX, key="#user.userid")
    public User update(User user, EntityWrapper<User> ew) {
        baseMapper.update(user, ew);
        return user;
    }

    @Override
    public User selectOne(EntityWrapper<User> ew) {
        return SqlHelper.getObject(baseMapper.selectList(ew));
    }

    @Override
    @Cacheable(value = CacheConstant.CACHE_PERSON_PREFIX, key="#userId")
    public User selectById(String userId) {
        logger.info("+++++++++++++++++++++从数据库拿数据—+++++++++++++++++++++++");
        return baseMapper.selectById(userId);
    }

}