• 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 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.EntityType;
import com.LG.model.HostHolder;
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;
}
}
}