「小程序JAVA实战」小程序的留言和评价功能（70）

转自：https://idig8.com/2018/10/28/xiaochengxujavashizhanxiaochengxudeliuyanhepingjiagongneng69/

目前小程序这块就只差留言功能了，从这次开始将对留言这个模块进行讲解和开发。源码：https://github.com/limingios/wxProgram.git 中No.15和springboot

后台开发

后台需要通过代码生成器针对留言表生成对应的pojo，mapper，mapper.xml，controller增加2个方法，一个添加留言，一个查看留言列表（分页显示）

• controoller
  > fatherCommentId 和 toUserId 主要针对的是评论功能，这里是把留言和评论设计在一张表里了

    @PostMapping("/saveComment")
    public JSONResult saveComment(@RequestBody Comments comment,
                                       String fatherCommentId, String toUserId) throws Exception {

        comment.setFatherCommentId(fatherCommentId);
        comment.setToUserId(toUserId);

        videosService.saveComment(comment);
        return JSONResult.ok();
    }

    @PostMapping("/getVideoComments")
    public JSONResult getVideoComments(String videoId, Integer page, Integer pageSize) throws Exception {

        if (StringUtils.isBlank(videoId)) {
            return JSONResult.ok();
        }

        // 分页查询视频列表，时间顺序倒序排序
        if (page == null) {
            page = 1;
        }

        if (pageSize == null) {
            pageSize = 10;
        }

        PagedResult list = videosService.getAllComments(videoId, page, pageSize);

        return JSONResult.ok(list);
    }

• service中添加2个方法
  >同controller，获取所有的留言列表功能，一个添加留言评价

@Transactional(propagation = Propagation.REQUIRED)
    @Override
    public void saveComment(Comments comment) {
        String id = sid.nextShort();
        comment.setId(id);
        comment.setCreateTime(new Date());
        commentMapper.insert(comment);
    }

    @Transactional(propagation = Propagation.SUPPORTS)
    @Override
    public PagedResult getAllComments(String videoId, Integer page, Integer pageSize) {

        PageHelper.startPage(page, pageSize);

        List<CommentsVO> list = commentMapperCustom.queryComments(videoId);

        for (CommentsVO c : list) {
            String timeAgo = TimeAgoUtils.format(c.getCreateTime());
            c.setTimeAgoStr(timeAgo);
        }

        PageInfo<CommentsVO> pageList = new PageInfo<>(list);

        PagedResult grid = new PagedResult();
        grid.setTotal(pageList.getPages());
        grid.setRows(list);
        grid.setPage(page);
        grid.setRecords(pageList.getTotal());

        return grid;
    }

• Vo类，方便页面展示评论人的信息，也方便mybatis查询的内容直接赋值

package com.idig8.pojo.vo;

import java.util.Date;
import javax.persistence.*;

import org.springframework.format.annotation.DateTimeFormat;

public class CommentsVO {
    private String id;

    /**
     * 视频id
     */
    private String videoId;

    /**
     * 留言者，评论的用户id
     */
    private String fromUserId;

    private Date createTime;

    /**
     * 评论内容
     */
    private String comment;

    private String faceImage;
    private String nickname;
    private String toNickname;
    private String timeAgoStr;

    public String getTimeAgoStr() {
        return timeAgoStr;
    }

    public void setTimeAgoStr(String timeAgoStr) {
        this.timeAgoStr = timeAgoStr;
    }

    public String getNickname() {
        return nickname;
    }

    public void setNickname(String nickname) {
        this.nickname = nickname;
    }

    public String getFaceImage() {
        return faceImage;
    }

    public void setFaceImage(String faceImage) {
        this.faceImage = faceImage;
    }

    /**
     * @return id
     */
    public String getId() {
        return id;
    }

    /**
     * @param id
     */
    public void setId(String id) {
        this.id = id;
    }

    /**
     * 获取视频id
     *
     * @return video_id - 视频id
     */
    public String getVideoId() {
        return videoId;
    }

    /**
     * 设置视频id
     *
     * @param videoId 视频id
     */
    public void setVideoId(String videoId) {
        this.videoId = videoId;
    }

    /**
     * 获取留言者，评论的用户id
     *
     * @return from_user_id - 留言者，评论的用户id
     */
    public String getFromUserId() {
        return fromUserId;
    }

    /**
     * 设置留言者，评论的用户id
     *
     * @param fromUserId 留言者，评论的用户id
     */
    public void setFromUserId(String fromUserId) {
        this.fromUserId = fromUserId;
    }

    /**
     * @return create_time
     */
    public Date getCreateTime() {
        return createTime;
    }

    /**
     * @param createTime
     */
    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }

    /**
     * 获取评论内容
     *
     * @return comment - 评论内容
     */
    public String getComment() {
        return comment;
    }

    /**
     * 设置评论内容
     *
     * @param comment 评论内容
     */
    public void setComment(String comment) {
        this.comment = comment;
    }

    public String getToNickname() {
        return toNickname;
    }

    public void setToNickname(String toNickname) {
        this.toNickname = toNickname;
    }
}

• CommentsMapperCustom 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.idig8.mapper.CommentsMapperCustom" >
  <resultMap id="BaseResultMap" type="com.idig8.pojo.vo.CommentsVO" >
    <!--
      WARNING - @mbg.generated
    -->
    <id column="id" property="id" jdbcType="VARCHAR" />
    <result column="video_id" property="videoId" jdbcType="VARCHAR" />
    <result column="from_user_id" property="fromUserId" jdbcType="VARCHAR" />
    <result column="create_time" property="createTime" jdbcType="TIMESTAMP" />
    <result column="comment" property="comment" jdbcType="LONGVARCHAR" />
    <result column="face_image" property="faceImage" jdbcType="VARCHAR" />
    <result column="nickname" property="nickname" jdbcType="VARCHAR" />
    <result column="toNickname" property="toNickname" jdbcType="VARCHAR" />
  </resultMap>

  <select id="queryComments" resultMap="BaseResultMap" parameterType="String">
    select c.*,u.face_image as face_image,u.nickname,tu.nickname as toNickname
    from comments c
    left join users u on c.from_user_id = u.id
    left join users tu on c.to_user_id = tu.id
    where c.video_id = #{videoId} order by c.create_time desc
  </select>

</mapper>

• mapper类 添加方法，方便调用

package com.idig8.mapper;

import java.util.List;

import com.idig8.pojo.Comments;
import com.idig8.pojo.vo.CommentsVO;
import com.idig8.utils.MyMapper;

public interface CommentsMapperCustom extends MyMapper<Comments> {

    public List<CommentsVO> queryComments(String videoId);
}

前台功能

videoInfo.wxml

<view class="saySthView">
<input name="commentContent" class="saySth" placeholder="{{placeholder}}" confirm-type="send" bindconfirm="saveComment" focus='{{commentFocus}}' value='{{contentValue}}'
data-replyFatherCommentId='{{replyFatherCommentId}}'
data-replyToUserId='{{replyToUserId}}'
/>
</view>

<block wx:for="{{commentsList}}">
  <view class='comments-all' bindtap='replyFocus'
  data-fatherCommentId='{{item.id}}'
  data-toUserId='{{item.fromUserId}}'
  data-toNickname='{{item.nickname}}'
  >
      <view class='container-comments'>
          <image class="face-comments" src='{{serverUrl}}{{item.faceImage}}' ></image>
          <view class='nickname-comments'>
              <label class='nickname-lbl'>@{{item.nickname}}</label>
              于
              <label class='date-lbl'>{{item.timeAgoStr}}</label>
              <!-- 留言： -->
              <block wx:if="{{item.toNickname != null}}">
                回复
                <label class='nickname-lbl'>@{{item.toNickname}}</label>
              </block>
              <block wx:else>
                留言：
              </block>
          </view>
      </view>
      <view class='comments-content'>{{item.comment}}</view>
  </view>
</block> 

</view>

• videoInfo.js

  leaveComment: function () {
    this.setData({
      commentFocus: true
    });
  },

  replyFocus: function (e) {
    var fatherCommentId = e.currentTarget.dataset.fathercommentid;
    var toUserId = e.currentTarget.dataset.touserid;
    var toNickname = e.currentTarget.dataset.tonickname;

    this.setData({
      placeholder: "回复  " + toNickname,
      replyFatherCommentId: fatherCommentId,
      replyToUserId: toUserId,
      commentFocus: true
    });
  },

  saveComment: function (e) {
    var me = this;
    var content = e.detail.value;

    // 获取评论回复的fatherCommentId和toUserId
    var fatherCommentId = e.currentTarget.dataset.replyfathercommentid;
    var toUserId = e.currentTarget.dataset.replytouserid;

    var user = app.getGlobalUserInfo();
    var videoInfo = JSON.stringify(me.data.videoInfo);
    var realUrl = '../videoinfo/videoinfo#videoInfo@' + videoInfo;

    if (user == null || user == undefined || user == '') {
      wx.navigateTo({
        url: '../userLogin/login?redirectUrl=' + realUrl,
      })
    } else {
      wx.showLoading({
        title: '请稍后...',
      })
      wx.request({
        url: app.serverUrl + '/video/saveComment?fatherCommentId=' + fatherCommentId + "&toUserId=" + toUserId,
        method: 'POST',
        header: {
          'content-type': 'application/json', // 默认值
          'headerUserId': user.id,
          'headerUserToken': user.userToken
        },
        data: {
          fromUserId: user.id,
          videoId: me.data.videoInfo.id,
          comment: content
        },
        success: function (res) {
          console.log(res.data)
          wx.hideLoading();

          me.setData({
            contentValue: "",
            commentsList: []
          });

          me.getCommentsList(1);
        }
      })
    }
  },

  // commentsPage: 1,
  //   commentsTotalPage: 1,
  //   commentsList: []

  getCommentsList: function (page) {
    var me = this;

    var videoId = me.data.videoInfo.id;

    wx.request({
      url: app.serverUrl + '/video/getVideoComments?videoId=' + videoId + "&page=" + page + "&pageSize=5",
      method: "POST",
      success: function (res) {
        console.log(res.data);

        var commentsList = res.data.data.rows;
        var newCommentsList = me.data.commentsList;

        me.setData({
          commentsList: newCommentsList.concat(commentsList),
          commentsPage: page,
          commentsTotalPage: res.data.data.total
        });
      }
    })
  },

  onReachBottom: function () {
    var me = this;
    var currentPage = me.data.commentsPage;
    var totalPage = me.data.commentsTotalPage;
    if (currentPage === totalPage) {
      return;
    }
    var page = currentPage + 1;
    me.getCommentsList(page);
  }

1. 为了方便点击某条留言，进行评论，需要设置（data-名称）
2. js获取（data-名称）的值是通过，e.currentTarget.dataset.名称
3. 赋值给评论列表里面的操作（data-名称）就可以了。
4. 按照顺序看下面的图

PS：其实都是基本操作，但是有个传值页面属性data绑定必须详细说下，这个很重要。