java+mysql简单实现点赞评论转发帖子

mysql表设计:

java代码

接口

  /**
     * 更新帖子点赞数 收藏数 同时更新中间表
     * @param topic
     * @param userId
     * @param type
     */
    void updateByTopic(Topic topic, Long userId, String type);

实现类：

 @Override
    public void updateByTopic(Topic topic, Long userId, String type) {
        TopicMiddleModel model = new TopicMiddleModel();
        model.setTopicId(topic.getId());
        model.setUserId(userId);
        List topicMiddles = topicMiddleSV.selectByModel(model);
        TopicMiddle topicMiddle = new TopicMiddle();
        if(topicMiddles != null && !topicMiddles.isEmpty()){
            topicMiddle = topicMiddles.get(0);
        }

    if("01".equals(type)){
        if(FlagEnum.IS.stringValue().equals(topicMiddle.getGoodFlag())){
            throw new BusinessException("该文章已经点过赞了");
        }
        topic.setGoodNum(topic.getGoodNum()+1);
        topicMiddle.setGoodFlag(FlagEnum.IS.stringValue());
    }else if("02".equals(type)){
        topic.setForwardNum(topic.getForwardNum()+1);
    }else if("03".equals(type)){
        if(FlagEnum.IS.stringValue().equals(topicMiddle.getCollect())){
            throw new BusinessException("该文章已经被收藏过了");
        }
        topic.setColNum(topic.getColNum()+1);
        topicMiddle.setCollect(FlagEnum.IS.stringValue());
    }else if ("04".equals(type)){
        if(FlagEnum.NO.stringValue().equals(topicMiddle.getGoodFlag())){
            throw new BusinessException("该文章还没有点过赞");
        }
        topic.setGoodNum(topic.getGoodNum()-1);
        topicMiddle.setGoodFlag(FlagEnum.NO.stringValue());
    }else if ("05".equals(type)){
        if((FlagEnum.NO.stringValue().equals(topicMiddle.getCollect()))){
            throw new BusinessException("该文章还没有被收藏过");
        }
        topic.setColNum(topic.getColNum()-1);
        topicMiddle.setCollect(FlagEnum.NO.stringValue());
    }else {
        throw new BusinessException("请传入01-06 有效值");
    }
    updateByIdSelective(topic);
    if(!"02".equals(type)){
        if(topicMiddles.isEmpty()){
            topicMiddle.setUserId(userId);
            topicMiddle.setTopicId(topic.getId());
            topicMiddleSV.insertSelective(topicMiddle);
        }else {
            topicMiddleSV.updateByIdSelective(topicMiddle);
        }
    }
}