实现实体评论服务

• 评论中心的实现

 

 

• 评论中心

需要评论的各种场景服务:

评论中心的设计：统一的评论服务，覆盖所有的实体，可以进行评论

通用的模块开发流程

1. Database Column

2. Model：模型定义，和数据库相匹配

3. DAO：数据读取

4. Service：服务包装

5. Controller：业务入口

6. Test

站内信开发流程

1. Database Column

id

content

entity_id ->questionId/commentId //表示任意实体的id；

entity_type question/comment //表示评论的对象

created_date

user_id

2. Model：模型定义，和数据库相匹配

package com.nowcoder.model;

 

import java.util.Date;

 

/**

* @Author liguo

* @Description

* @Data 2018-09-06 7:50

*/

public class Comment {

private int id;

private int userId;

private int entityId;

private int entityType;

private String content;

private Date createdDate;

private int status;

 

public int getId() {

return id;

}

 

public void setId(int id) {

this.id = id;

}

 

public int getUserId() {

return userId;

}

 

public void setUserId(int userId) {

this.userId = userId;

}

 

public int getEntityId() {

return entityId;

}

 

public void setEntityId(int entityId) {

this.entityId = entityId;

}

 

public int getEntityType() {

return entityType;

}

 

public void setEntityType(int entityType) {

this.entityType = entityType;

}

 

public String getContent() {

return content;

}

 

public void setContent(String content) {

this.content = content;

}

 

public Date getCreatedDate() {

return createdDate;

}

 

public void setCreatedDate(Date createdDate) {

this.createdDate = createdDate;

}

 

public int getStatus() {

return status;

}

 

public void setStatus(int status) {

this.status = status;

}

}

 

3. DAO：数据读取

 

//数据库接口的crud

@Mapper

public interface CommentDAO {

String TABLE_NAME = " comment ";

String INSERT_FIELDS = " user_id, content, created_date, entity_id, entity_type, status ";

String SELECT_FIELDS = " id, " + INSERT_FIELDS;

 

@Insert({"insert into ", TABLE_NAME, "(", INSERT_FIELDS,

") values (#{userId},#{content},#{createdDate},#{entityId},#{entityType},#{status})"})

int addComment(Comment comment);

 

@Select({"select ", SELECT_FIELDS, " from ", TABLE_NAME, " where id=#{id}"})

Comment getCommentById(int id);

 

@Select({"select ", SELECT_FIELDS, " from ", TABLE_NAME,

" where entity_id=#{entityId} and entity_type=#{entityType} order by created_date desc"})

List<Comment> selectCommentByEntity(@Param("entityId") int entityId, @Param("entityType") int entityType);

 

@Select({"select count(id) from ", TABLE_NAME, " where entity_id=#{entityId} and entity_type=#{entityType}"})

int getCommentCount(@Param("entityId") int entityId, @Param("entityType") int entityType);

 

@Update({"update comment set status=#{status} where id=#{id}"})

int updateStatus(@Param("id") int id, @Param("status") int status);

 

@Select({"select count(id) from ", TABLE_NAME, " where user_id=#{userId}"})

int getUserCommentCount(int userId);

 

4. Service：服务包装

package com.LG.service;

 

import com.LG.dao.CommentDAO;

import com.LG.model.Comment;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Service;

import org.springframework.web.util.HtmlUtils;

 

import java.util.List;

 

/**

* @Author liguo

* @Description

* @Data 2018-09-06 8:54

*/

 

@Service

public class CommentService {

@Autowired

CommentDAO commentDAO;

 

@Autowired

SensitiveService sensitiveService;

 

public List <Comment> getCommentsByEntity(int entityId, int entityType) {

return commentDAO.selectCommentByEntity( entityId, entityType );

}

//过滤敏感词后进行插入

public int addComment(Comment comment) {

comment.setContent( HtmlUtils.htmlEscape( comment.getContent() ) );

comment.setContent( sensitiveService.filter( comment.getContent() ) );

return commentDAO.addComment( comment ) > 0 ? comment.getId() : 0;

}

 

public int getCommentCount(int entityId, int entityType) {

return commentDAO.getCommentCount( entityId, entityType );

}

 

public int getUserCommentCount(int userId) {

return commentDAO.getUserCommentCount( userId );

}

 

public boolean deleteComment(int commentId) {

return commentDAO.updateStatus( commentId, 1 ) > 0;

}

 

public Comment getCommentById(int id) {

return commentDAO.getCommentById( id );

}

 

}

5. Controller：业务入口

package com.LG.controller;

 

import com.LG.async.EventModel;

import com.LG.async.EventProducer;

import com.LG.async.EventType;

import com.LG.model.Comment;

import com.LG.model.EntityType;

import com.LG.model.HostHolder;

import com.LG.service.CommentService;

import com.LG.service.QuestionService;

import com.LG.util.WendaUtil;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestMethod;

import org.springframework.web.bind.annotation.RequestParam;

 

import java.util.Date;

 

/**

* @Author liguo

* @Description

* @Data 2018-09-06 8:53

*/

 

@Controller

public class CommentController {

private static final Logger logger = LoggerFactory.getLogger(CommentController.class);

@Autowired

HostHolder hostHolder;

 

@Autowired

CommentService commentService;

 

@Autowired

QuestionService questionService;

 

@Autowired

EventProducer eventProducer;

 

 

@RequestMapping(path = {"/addComment"}, method = {RequestMethod.POST})

public String addComment(@RequestParam("questionId") int questionId,

@RequestParam("content") String content) {

try {

Comment comment = new Comment();

comment.setContent(content);

if (hostHolder.getUser() != null) {

comment.setUserId(hostHolder.getUser().getId());

} else {

comment.setUserId( WendaUtil.ANONYMOUS_USERID );

// return "redirect:/reglogin";

}

comment.setCreatedDate(new Date());

comment.setEntityType( EntityType.ENTITY_QUESTION );

comment.setEntityId(questionId);

commentService.addComment(comment);

 

int count = commentService.getCommentCount(comment.getEntityId(), comment.getEntityType());

questionService.updateCommentCount(comment.getEntityId(), count);

 

eventProducer.fireEvent( new EventModel( EventType.COMMENT ).setActorId( comment.getUserId() )

.setEntityId(questionId));

 

} catch (Exception e) {

logger.error("增加评论失败" + e.getMessage());

}

return "redirect:/question/" + questionId;

}

}

}