粉丝关注

业务逻辑:

1. 判断参数是否合法
2. 根据writerId查询用户信息
3. 新建粉丝对象 并将用户信息和基本设置到粉丝对象中
4. 进行插入操作 redis粉丝数 + 1

controller

    public GraceJSONResult follow(String writerId, String fanId) {
        // 0. 判断参数是否合法
        if (StringUtils.isBlank(writerId) || StringUtils.isBlank(fanId)) {

            GraceException.display(ResponseStatusEnum.USERNAME_NOTFOUND);
        }

        fanService.addFans(writerId, fanId);

        return GraceJSONResult.ok();
    }

service

    @Transactional
    public void addFans(String writerId, String fanId) {
        // 思路: 1. 根据用户id 将用户信息查询出来 2. 将用户信息设置到fans对象中 3. 执行插入操作 4. 修改redis 粉丝数
        AppUser appUser = userMapper.selectById(writerId);

        if (appUser == null) {
            GraceException.display(ResponseStatusEnum.USER_NOT_EXIST_ERROR);
        }

        Fans fans = new Fans();
        fans.setWriterId(writerId);
        fans.setFanId(fanId);
        fans.setFace(appUser.getFace());
        fans.setFanNickname(appUser.getNickname());
        fans.setSex(appUser.getSex());
        fans.setProvince(appUser.getProvince());

        fanMapper.insert(fans);

        redisOperator.increment(REDIS_WRITER_FOLLOW_COUNTS + ":" + writerId, 1);
        redisOperator.increment(REDIS_MY_FOLLOW_COUNTS + ":" + fanId, 1);
    }