【MyBatisPlus】获取多级评论列表

绝地灬酷狼 2023-10-11 23:28 1阅读 0赞

![6b8e8423a534463490f1abcce98da505.png][]

### 后端代码：（思想类似树的层次遍历，再用for循环维护好一个动态遍历列表就好了） ###

/**
         * 根据视频id查询所有评论
         * 从第一层开始一层一层往下找
         */
        @GetMapping("/comment/{id}")
        public Result<List<Comment>> getComment(@PathVariable Long id){
            QueryWrapper<Comment> queryWrapper = new QueryWrapper<>();
            queryWrapper.eq("video_id", id).eq("parent_id", 0);
            // lists为第一级
            List<Comment> lists = commentService.getBaseMapper().selectList(queryWrapper);
            // 只能展示二级评论，增强型for循环不能动态添加数组元素
    //        for(Comment list : lists) {
    //            QueryWrapper<Comment> queryWrapper1 = new QueryWrapper<>();
    //            queryWrapper1.eq("parent_id", list.getId());
    //            List<Comment> lists1 = commentService.getBaseMapper().selectList(queryWrapper1);
    //            list.setChild(lists1);
    //        }
            int n = lists.size();
            for(int i = 0; i < lists.size(); i++){
                QueryWrapper<Comment> queryWrapper1 = new QueryWrapper<>();
                queryWrapper1.eq("parent_id", lists.get(i).getId());
                List<Comment> lists1 = commentService.getBaseMapper().selectList(queryWrapper1);
                lists.get(i).setChild(lists1);
                lists.get(i).setUserInfo(userInfoFeign.getUserInfo(lists.get(i).getUserId()).getData());
                // 取父评论的用户id
                if(lists.get(i).getParentId()!=0){
                    QueryWrapper<Comment> queryWrapper2 = new QueryWrapper<>();
                    queryWrapper2.eq("id", lists.get(i).getParentId());
                    Comment comment = commentService.getBaseMapper().selectOne(queryWrapper2);
                    lists.get(i).setParentInfo(userInfoFeign.getUserInfo(comment.getUserId()).getData());
                }
                lists.addAll(lists1);
            }
            // 剪枝操作
            for(int i = lists.size(); i > n; i--){
                lists.remove(i - 1);
            }
            return Result.success(lists);
        }

[6b8e8423a534463490f1abcce98da505.png]: https://img-blog.csdnimg.cn/6b8e8423a534463490f1abcce98da505.png