根据上节的开发安排：显示评论功能完成后，开始实现添加评论功能。
CommentMapper类中添加insertComment方法。
discuss_post中的comment_count为冗余数据，DiscussPostMapper类中添加updateCommentCount方法。
package com.gerrard.community.dao;
import com.gerrard.community.entity.Comment;
import org.apache.ibatis.annotations.Mapper;
import java.util.List;
@Mapper
public interface CommentMapper {
List<Comment> selectCommentsByEntity(int entityType, int entityId, int offset, int limit);
int selectCountByEntity(int entityType, int entityId);
int insertComment(Comment comment);
}
comment-mapper.xml:
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.gerrard.community.dao.CommentMapper">
<sql id="selectFields">
id, user_id, entity_type, entity_id, target_id, content, status, create_time
</sql>
<sql id="insertFields">
user_id, entity_type, entity_id, target_id, content, status, create_time
</sql>
<select id="selectCommentsByEntity" resultType="Comment">
select <include refid="selectFields"></include>
from comment
where status = 0
and entity_type = #{entityType}
and entity_id = #{entityId}
order by create_time asc
limit #{offset}, #{limit}
</select>
<select id="selectCountByEntity" resultType="int">
select count(id)
from comment
where status = 0
and entity_type = #{entityType}
and entity_id = #{entityId}
</select>
<insert id="insertComment" parameterType="Comment">
insert into comment(<include refid="insertFields"></include>)
values(#{userId},#{entityType},#{entityId},#{targetId},#{content},#{status},#{createTime})
</insert>
</mapper>
package com.gerrard.community.dao;
import com.gerrard.community.entity.DiscussPost;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import java.util.List;
@Mapper
public interface DiscussPostMapper {
List<DiscussPost> selectDiscussPosts(int userId, int offset, int limit);
// @Param注解用于给参数取别名,
// 如果只有一个参数,并且在<if>里使用,则必须加别名.
int selectDiscussPostRows(@Param("userId") int userId);
int insertDiscussPost(DiscussPost discussPost);
DiscussPost selectDiscussPostById(int id);
int updateCommentCount(int id, int commentCount);
}
discusspost-mapper.xml：
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.gerrard.community.dao.DiscussPostMapper">
<sql id="selectFields">
id, user_id, title, content, type, status, create_time, comment_count, score
</sql>
<sql id="insertFields">
user_id, title, content, type, status, create_time, comment_count, score
</sql>
<select id="selectDiscussPosts" resultType="DiscussPost">
select <include refid="selectFields"></include>
from discuss_post
where status != 2
<if test="userId!=0">
and user_id = #{userId}
</if>
order by type desc, create_time desc
limit #{offset}, #{limit}
</select>
<select id="selectDiscussPostRows" resultType="int">
select count(id)
from discuss_post
where status != 2
<if test="userId!=0">
and user_id = #{userId}
</if>
</select>
<insert id="insertDiscussPost" parameterType="DiscussPost">
insert into discuss_post(<include refid="insertFields"></include>)
values(#{userId},#{title},#{content},#{type},#{status},#{createTime},#{commentCount},#{score})
</insert>
<select id="selectDiscussPostById" resultType="DiscussPost">
select <include refid="selectFields"></include>
from discuss_post
where id = #{id}
</select>
<update id="updateCommentCount">
update discuss_post set comment_count = #{commentCount} where id = #{id}
</update>
</mapper>
CommentService中添加addComment方法（用到事务注解，涉及两张表操作），DiscussPostService中添加updateCommentCount方法。
package com.gerrard.community.service;
import com.gerrard.community.dao.CommentMapper;
import com.gerrard.community.entity.Comment;
import com.gerrard.community.util.CommunityConstant;
import com.gerrard.community.util.SensitiveFilter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Isolation;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.util.HtmlUtils;
import java.util.List;
@Service
public class CommentService implements CommunityConstant {
@Autowired
private CommentMapper commentMapper;
@Autowired
private SensitiveFilter sensitiveFilter;
@Autowired
private DiscussPostService discussPostService;
public List<Comment> findCommentsByEntity(int entityType, int entityId, int offset, int limit) {
return commentMapper.selectCommentsByEntity(entityType, entityId, offset, limit);
}
public int findCommentCount(int entityType, int entityId) {
return commentMapper.selectCountByEntity(entityType, entityId);
}
@Transactional(isolation = Isolation.READ_COMMITTED, propagation = Propagation.REQUIRED)
public int addComment(Comment comment) {
if (comment == null) {
throw new IllegalArgumentException("参数不能为空!");
}
// 添加评论
comment.setContent(HtmlUtils.htmlEscape(comment.getContent()));
comment.setContent(sensitiveFilter.filter(comment.getContent()));
int rows = commentMapper.insertComment(comment);
// 更新帖子评论数量
if (comment.getEntityType() == ENTITY_TYPE_POST) {
int count = commentMapper.selectCountByEntity(comment.getEntityType(), comment.getEntityId());
discussPostService.updateCommentCount(comment.getEntityId(), count);
}
return rows;
}
}
package com.gerrard.community.service;
import com.gerrard.community.dao.DiscussPostMapper;
import com.gerrard.community.entity.DiscussPost;
import com.gerrard.community.util.SensitiveFilter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.util.HtmlUtils;
import java.util.List;
@Service
public class DiscussPostService {
@Autowired
private DiscussPostMapper discussPostMapper;
@Autowired
private SensitiveFilter sensitiveFilter;
public List<DiscussPost> findDiscussPosts(int userId, int offset, int limit) {
return discussPostMapper.selectDiscussPosts(userId, offset, limit);
}
public int findDiscussPostRows(int userId) {
return discussPostMapper.selectDiscussPostRows(userId);
}
public int addDiscussPost(DiscussPost post) {
if (post == null) {
throw new IllegalArgumentException("参数不能为空!");
}
// 转义HTML标记
post.setTitle(HtmlUtils.htmlEscape(post.getTitle()));
post.setContent(HtmlUtils.htmlEscape(post.getContent()));
// 过滤敏感词
post.setTitle(sensitiveFilter.filter(post.getTitle()));
post.setContent(sensitiveFilter.filter(post.getContent()));
return discussPostMapper.insertDiscussPost(post);
}
public DiscussPost findDiscussPostById(int id) {
return discussPostMapper.selectDiscussPostById(id);
}
public int updateCommentCount(int id, int commentCount) {
return discussPostMapper.updateCommentCount(id, commentCount);
}
}
添加CommentController类。
package com.gerrard.community.controller;
import com.gerrard.community.entity.Comment;
import com.gerrard.community.service.CommentService;
import com.gerrard.community.util.HostHolder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import java.util.Date;
@Controller
@RequestMapping("/comment")
public class CommentController {
@Autowired
private CommentService commentService;
@Autowired
private HostHolder hostHolder;
@RequestMapping(path = "/add/{discussPostId}", method = RequestMethod.POST)
public String addComment(@PathVariable("discussPostId") int discussPostId, Comment comment) {
comment.setUserId(hostHolder.getUser().getId());
comment.setStatus(0);
comment.setCreateTime(new Date());
commentService.addComment(comment);
return "redirect:/discuss/detail/" + discussPostId;
}
}
entityId，entityType，【targetId】由前端传入。
用户进行回复，获取comment实体类信息，将comment实体类插入到comment数据库中，再更新discuss_post数据库中comment_count字段（用到事务操作）。
有三种回复，一种需要传targetId，其他targetId默认为0
comment数据库信息查看：
