评论回复功能的设计与实现

末蓝、 2023-07-15 09:07 22阅读 0赞

评论回复功能的数据库设计可以分开设计成两张表，评论表和回复表，也可以将其设计为一张表，我采用的是一张表  
评论回复表的相关字段（我做的是商品goods下的评论回复）  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4MTU3ODI1_size_16_color_FFFFFF_t_70]  
字段解释：

gc_id：评论回复表id
    gc_uid：评论用户id（外键）
    gc_content：评论内容
    gc_time：评论时间
    gc_gid：评论的商品id（外键）
    gc_status：评论状态（1未删除0已删除）
    gc_parentid：父级评论的id，如果不是对评论的回复，那么该值为null

我在评论回复表中添加了几条数据  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4MTU3ODI1_size_16_color_FFFFFF_t_70 1]  
接下来是代码部分了  
采用的是 `springboot`\+`mybatis`  
1.`GoodsComment` 的pojo类

public class GoodsComment { 
        private Integer gcId;
        private Integer gcGid;
        private Integer gcUid;
        private Date gcTime;
        private String gcContent;
        private Integer gcStatus;
        private Integer gcParentid;
        private Goods goods;
        private Users users;
        private List<GoodsComment> child;
    
    	// 略去了getter和setter方法
    }

2.`GoodsCommentMapper.java`

public interface GoodsCommentMapper { 
        // 根据商品id查询该商品下的所有评论
        List<GoodsComment> findByGoodId(@Param("gId") Integer gId);
    }

3.`GoodsCommentService.java`

public interface GoodsCommentService { 
        // 根据商品id查询该商品下的所有评论
        List<GoodsComment> findByGoodId(Integer gId);
    }

4.`GoodsCommentServiceImpl.java`

@Service
    public class GoodsCommentServiceImpl implements GoodsCommentService { 
        @Resource
        private GoodsCommentMapper goodsCommentMapper;
    
        @Override
        public List<GoodsComment> findByGoodId(Integer gId) { 
            return goodsCommentMapper.findByGoodId(gId);
        }
    }

5.`GoodsCommentMapper.xml`

<select id="findByGoodId" resultMap="BaseResultMap">
        SELECT a.*,b.*
        FROM goods_comment AS a,users AS b
        WHERE a.gc_gId=#{gId}
        AND a.gc_status=b.u_status=1
        AND a.gc_uid=b.u_id
    </select>

6.`CoodsCommentController.java`

@RestController
    @RequestMapping("/goodsComment")
    public class GoodsCommentController { 
    
        @Autowired
        private GoodsCommentService commentService;
    
        /** * 根据商品id查询该商品下的所有评论 * @param gId * @return */
        @GetMapping("/findByGoodId/{gId}")
        public List<GoodsComment> findByGoodId(@PathVariable("gId") Integer gId) { 
            List<GoodsComment> allComments = commentService.findByGoodId(gId);
            if (allComments == null || allComments.size() == 0) { 
                return new ArrayList<>();
            }
            List<GoodsComment> comments = new ArrayList<>();
            List<GoodsComment> parents = new ArrayList<>();
            for (GoodsComment comment : allComments) { 
                if (comment.getGcParentid()==null) { 
                    comments.add(comment);
                    parents.add(comment);
                } else { 
                    boolean foundParent=false;
                    for (GoodsComment parent : parents) { 
                        if (comment.getGcParentid() == parent.getGcId()) { 
                            if (parent.getChild() == null) { 
                                parent.setChild(new ArrayList<>());
                            }
                            parent.getChild().add(comment);
                            parents.add(comment);
                            foundParent=true;
                            //如果对list迭代过程中同时修改list，会报java.util.ConcurrentModificationException
                            // 的异常，所以我们需要break,当然break也可以提高算法效率
                            break;
                        }
                    }
                    if (!foundParent) { 
                        throw new RuntimeException("can not find the parent comment");
                    }
                }
            }
            return comments;
        }
    }

7.获取到的数据部分

[
        { 
            "gcId": 1,
            "gcGid": 1,
            "gcUid": 11,
            "gcTime": "2020-03-13T14:29:52.000+0000",
            "gcContent": "我是评论商品的",
            "gcStatus": 1,
            "gcParentid": null,
            "goods": null,
            "users": { 
                "uId": 11,
                "uName": "小陈",
                "uAvatar": "http://imgs/FjrnXL4DP6Ib8xmZmXQU5vy5GWvq"
            },
            "child": [
                { 
                    "gcId": 3,
                    "gcGid": 1,
                    "gcUid": 6,
                    "gcTime": "2020-03-15T16:31:49.000+0000",
                    "gcContent": "我是回复",
                    "gcStatus": 1,
                    "gcParentid": 1,
                    "goods": null,
                    "users": { 
                        "uId": 6,
                        "uName": "小贰",
                        "uAvatar": "http://imgs/Fi-WU4zsZ-1OTVfPg5OXyIao13SP"
                    },
                    "child": [
                        { 
                            "gcId": 4,
                            "gcGid": 1,
                            "gcUid": 10,
                            "gcTime": "2020-03-15T16:48:15.000+0000",
                            "gcContent": "我是回复的回复",
                            "gcStatus": 1,
                            "gcParentid": 3,
                            "goods": null,
                            "users": { 
                                "uId": 10,
                                "uName": "小贰",
                                "uAvatar": "http://imgs/Fi-WU4zsZ-1OTVfPg5OXyIao13SP"
                            },
                            "child": [
                                { 
                                    "gcId": 5,
                                    "gcGid": 1,
                                    "gcUid": 9,
                                    "gcTime": "2020-03-15T20:26:09.000+0000",
                                    "gcContent": "我看一下新增评论",
                                    "gcStatus": 1,
                                    "gcParentid": 4,
                                    "goods": null,
                                    "users": { 
                                        "uId": 9,
                                        "uName": "小贰",
                                        "uAvatar": "http://imgs/Fi-WU4zsZ-1OTVfPg5OXyIao13SP"
                                    },
                                    "child": null
                                }
                            ]
                        }
                    ]
                }
            ]
        },
        { 
            "gcId": 2,
            "gcGid": 1,
            "gcUid": 8,
            "gcTime": "2020-03-14T14:30:12.000+0000",
            "gcContent": "我也是评论这个商品的",
            "gcStatus": 1,
            "gcParentid": null,
            "goods": null,
            "users": { 
                "uId": 8,
                "uName": "小贰",
                "uAvatar": "http://imgs/Fi-WU4zsZ-1OTVfPg5OXyIao13SP"
            },
            "child": null
        }
     ]

评论的样式  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4MTU3ODI1_size_16_color_FFFFFF_t_70 2]

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