转自：https://idig8.com/2018/09/24/xiaochengxujavashizhanxiaochengxudeguanzhugongneng64/

在个人页面，根据发布者个人和个人的信息来进行展示，如果是发布者，可以进行关注和取消关注。

后端开发

涉及2涨表，一个关联表，个人和粉丝的关联表，用户表。

UsersMapper.java

package com.idig8.mapper;

import com.idig8.pojo.Users;
import com.idig8.utils.MyMapper;

public interface UsersMapper extends MyMapper<Users> {

    public void addReceiveLikeCount(String userId);

    public void reduceReceiveLikeCount(String userId);

    /**
     * @Description: 增加粉丝数
     */
    public void addFansCount(String userId);

    /**
     * @Description: 增加关注数
     */
    public void addFollersCount(String userId);

    /**
     * @Description: 减少粉丝数
     */
    public void reduceFansCount(String userId);

    /**
     * @Description: 减少关注数
     */
    public void reduceFollersCount(String userId);

}

UsersMapper.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.UsersMapper" >
  <resultMap id="BaseResultMap" type="com.idig8.pojo.Users" >
    <!--
      WARNING - @mbg.generated
    -->
    <id column="id" property="id" jdbcType="VARCHAR" />
    <result column="username" property="username" jdbcType="VARCHAR" />
    <result column="password" property="password" jdbcType="VARCHAR" />
    <result column="face_image" property="faceImage" jdbcType="VARCHAR" />
    <result column="nickname" property="nickname" jdbcType="VARCHAR" />
    <result column="fans_counts" property="fansCounts" jdbcType="INTEGER" />
    <result column="follow_counts" property="followCounts" jdbcType="INTEGER" />
    <result column="receive_like_counts" property="receiveLikeCounts" jdbcType="INTEGER" />
  </resultMap>

  <update id="addReceiveLikeCount" parameterType="String">
    update users set receive_like_counts = receive_like_counts+1 where id=#{userId}
  </update>

    <update id="reduceReceiveLikeCount" parameterType="String">
    update users set receive_like_counts = receive_like_counts-1 where id=#{userId}
  </update>

   <update id="addFansCount" parameterType="String">
    update users set fans_counts=fans_counts+1 where id=#{userId}
  </update>

  <update id="reduceFansCount" parameterType="String">
    update users set fans_counts=fans_counts-1 where id=#{userId}
  </update>

  <update id="addFollersCount" parameterType="String">
    update users set follow_counts=follow_counts+1 where id=#{userId}
  </update>

  <update id="reduceFollersCount" parameterType="String">
    update users set follow_counts=follow_counts-1 where id=#{userId}
  </update>

</mapper>

UserController.java

package com.idig8.controller;

import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import com.idig8.pojo.Users;
import com.idig8.pojo.vo.PublisherVideo;
import com.idig8.pojo.vo.UsersVO;
import com.idig8.service.UserService;
import com.idig8.utils.JSONResult;
import com.idig8.utils.file.FileUtil;

import io.swagger.annotations.Api;
import io.swagger.annotations.ApiImplicitParam;
import io.swagger.annotations.ApiImplicitParams;
import io.swagger.annotations.ApiOperation;
import io.swagger.annotations.ApiParam;

@RestController
@Api(value="用户接口",tags={"用户的controller"})
@RequestMapping(value = "/user")
public class UserController extends BasicController{

    @Autowired
    private UserService userService;

    @Value("${server.file.path}")
    private String fileSpace;

    @ApiOperation(value="用户上传头像",notes="用户上传头像的接口")
    @ApiImplicitParams({
        @ApiImplicitParam(name="userId",value="用户id",required=true,dataType="String",paramType="query"),
    })
    @PostMapping(value="/uploadFace",headers="content-type=multipart/form-data")
    public JSONResult uploadFace(String userId,@ApiParam(value="图片",required=true) MultipartFile file) {
        if (StringUtils.isBlank(userId)) {
            return JSONResult.errorMsg("用户id不能为空...");
        }

        // 文件保存的命名空间
        String fileName = file.getOriginalFilename();
        // 保存到数据库中的相对路径
        String path = "";
         try {
             path = FileUtil.uploadFile(file.getBytes(), fileSpace, fileName);
            } catch (Exception e) {
                e.getStackTrace();
                return JSONResult.errorMsg(e.getMessage());
            }

         Users user = new Users();
         user.setId(userId);
         user.setFaceImage(path);
         userService.updateUser(user);


        return JSONResult.ok(path);
    }

    @ApiOperation(value="通过用户Id获取用户信息",notes="通过用户Id获取用户信息的接口")
    @ApiImplicitParam(name="userId",value="用户id",required=true,dataType="String",paramType="query")
    @PostMapping("/queryByUserId")
    public JSONResult queryByUserId(String userId, String fanId) {
        if (StringUtils.isBlank(userId)) {
            return JSONResult.errorMsg("用户id不能为空...");
        }

        Users user = userService.queryUserId(userId);
        UsersVO usersVO= new UsersVO();
        BeanUtils.copyProperties(user, usersVO);

        usersVO.setFollow(userService.queryIfFollow(userId, fanId));
        return JSONResult.ok(usersVO);
    }

    @PostMapping("/queryPublisher")
    public JSONResult queryPublisher(String loginUserId, String videoId, 
            String publishUserId) throws Exception {

        if (StringUtils.isBlank(publishUserId)) {
            return JSONResult.errorMsg("");
        }

        // 1. 查询视频发布者的信息
        Users userInfo = userService.queryUserInfo(publishUserId);
        UsersVO publisher = new UsersVO();
        BeanUtils.copyProperties(userInfo, publisher);

        // 2. 查询当前登录者和视频的点赞关系
        boolean userLikeVideo = userService.isUserLikeVideo(loginUserId, videoId);

        PublisherVideo bean = new PublisherVideo();
        bean.setPublisher(publisher);   
        bean.setUserLikeVideo(userLikeVideo);

        return JSONResult.ok(bean);
    }


    @PostMapping("/beyourfans")
    public JSONResult beyourfans(String userId, String fanId) throws Exception {

        if (StringUtils.isBlank(userId) || StringUtils.isBlank(fanId)) {
            return JSONResult.errorMsg("");
        }

        userService.saveUserFanRelation(userId, fanId);

        return JSONResult.ok("关注成功...");
    }

    @PostMapping("/dontbeyourfans")
    public JSONResult dontbeyourfans(String userId, String fanId) throws Exception {

        if (StringUtils.isBlank(userId) || StringUtils.isBlank(fanId)) {
            return JSONResult.errorMsg("");
        }

        userService.deleteUserFanRelation(userId, fanId);

        return JSONResult.ok("取消关注成功...");
    }


}

UserService.java

package com.idig8.service;

import com.idig8.pojo.Users;

public interface UserService {

    /**
     * 判断用户名是否存在
     * @param username
     * @return
     */
    public boolean queryUsernameIsExist(String username);

    /**
     * 保存用户
     * @param user
     * @return
     */
    public void saveUser(Users user);

    /**
     * 查询用户对象
     * @param username
     * @return
     */
    public Users queryUserIsExist(Users user);

    /**
     * 更新对象
     * @param username
     * @return
     */
    public void updateUser(Users user);


    /**
     * userId查询用户对象
     * @param username
     * @return
     */
    public Users queryUserId(String userId);

    /**
     * 查询用户信息
     */
    public Users queryUserInfo(String userId);

    /**
     * 查询用户是否喜欢点赞视频
     */
    public boolean isUserLikeVideo(String userId, String videoId);

    /**
     * @Description: 增加用户和粉丝的关系
     */
    public void saveUserFanRelation(String userId, String fanId);

    /**
     * @Description: 删除用户和粉丝的关系
     */
    public void deleteUserFanRelation(String userId, String fanId);

    /**
     * @Description: 查询用户是否关注
     */
    public boolean queryIfFollow(String userId, String fanId);


}

UserServiceImpl.java

package com.idig8.service.Impl;

import java.util.List;

import org.apache.commons.lang3.StringUtils;
import org.n3r.idworker.Sid;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;

import com.idig8.mapper.UsersFansMapper;
import com.idig8.mapper.UsersLikeVideosMapper;
import com.idig8.mapper.UsersMapper;
import com.idig8.pojo.Users;
import com.idig8.pojo.UsersFans;
import com.idig8.pojo.UsersLikeVideos;
import com.idig8.service.UserService;
import com.idig8.utils.MD5Utils;

import tk.mybatis.mapper.entity.Example;
import tk.mybatis.mapper.entity.Example.Criteria;

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UsersMapper usersMapper;

    @Autowired
    private UsersLikeVideosMapper usersLikeVideosMapper;

    @Autowired
    private UsersMapper userMapper;

    @Autowired
    private Sid sid;

    @Autowired
    private UsersFansMapper usersFansMapper;

    @Transactional(propagation =Propagation.SUPPORTS)
    @Override
    public boolean queryUsernameIsExist(String username) {
        Users user = new Users();
        user.setUsername(username);
        Users result = usersMapper.selectOne(user);
        return result==null? false:true;
    }

    @Transactional(propagation =Propagation.REQUIRED)
    @Override
    public void saveUser(Users user) {
        String userId =sid.nextShort();
        user.setId(userId);
        usersMapper.insert(user);
    }

    @Transactional(propagation =Propagation.SUPPORTS)
    @Override
    public Users queryUserIsExist(Users user) {
        Example queryExample = new Example(Users.class);
        Criteria criteria = queryExample.createCriteria();
        criteria.andEqualTo("username",user.getUsername());
        try {
            criteria.andEqualTo("password",MD5Utils.getMD5Str(user.getPassword()));
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        Users userOne =  usersMapper.selectOneByExample(queryExample);
        return userOne;
    }

    @Transactional(propagation =Propagation.REQUIRED)
    @Override
    public void updateUser(Users user) {

        Example userExample = new Example(Users.class);
        Criteria criteria = userExample.createCriteria();
        criteria.andEqualTo("id", user.getId());
        usersMapper.updateByExampleSelective(user, userExample);
    }

    @Transactional(propagation =Propagation.SUPPORTS)
    @Override
    public Users queryUserId(String userId){
        Example queryExample = new Example(Users.class);
        Criteria criteria = queryExample.createCriteria();
        criteria.andEqualTo("id",userId);
        Users userOne =  usersMapper.selectOneByExample(queryExample);
        return userOne;
    }

    @Transactional(propagation = Propagation.SUPPORTS)
    @Override
    public Users queryUserInfo(String userId) {
        Example userExample = new Example(Users.class);
        Criteria criteria = userExample.createCriteria();
        criteria.andEqualTo("id", userId);
        Users user = userMapper.selectOneByExample(userExample);
        return user;
    }

    @Transactional(propagation = Propagation.SUPPORTS)
    @Override
    public boolean isUserLikeVideo(String userId, String videoId) {

        if (StringUtils.isBlank(userId) || StringUtils.isBlank(videoId)) {
            return false;
        }

        Example example = new Example(UsersLikeVideos.class);
        Criteria criteria = example.createCriteria();

        criteria.andEqualTo("userId", userId);
        criteria.andEqualTo("videoId", videoId);

        List<UsersLikeVideos> list = usersLikeVideosMapper.selectByExample(example);

        if (list != null && list.size() >0) {
            return true;
        }

        return false;
    }

    @Transactional(propagation = Propagation.REQUIRED)
    @Override
    public void saveUserFanRelation(String userId, String fanId) {

        String relId = sid.nextShort();

        UsersFans userFan = new UsersFans();
        userFan.setId(relId);
        userFan.setUserId(userId);
        userFan.setFanId(fanId);

        usersFansMapper.insert(userFan);

        userMapper.addFansCount(userId);
        userMapper.addFollersCount(fanId);

    }

    @Transactional(propagation = Propagation.REQUIRED)
    @Override
    public void deleteUserFanRelation(String userId, String fanId) {

        Example example = new Example(UsersFans.class);
        Criteria criteria = example.createCriteria();

        criteria.andEqualTo("userId", userId);
        criteria.andEqualTo("fanId", fanId);

        usersFansMapper.deleteByExample(example);

        userMapper.reduceFansCount(userId);
        userMapper.reduceFollersCount(fanId);

    }


    @Override
    public boolean queryIfFollow(String userId, String fanId) {

        Example example = new Example(UsersFans.class);
        Criteria criteria = example.createCriteria();

        criteria.andEqualTo("userId", userId);
        criteria.andEqualTo("fanId", fanId);

        List<UsersFans> list = usersFansMapper.selectByExample(example);

        if (list != null && !list.isEmpty() && list.size() > 0) {
            return true;
        }

        return false;
    }

}

前端小程序

<view>

  <view class=‘container‘>
      <image src="{{faceImage}}" class="face" bindtap=‘uploadFace‘></image>
    <label class=‘nickname‘>{{nickname}}</label>

    <block wx:if=‘{{isMe}}‘>
      <button size=‘mini‘ class=‘primary‘ bindtap=‘uploadVideo‘> 上传作品</button>
      <button size=‘mini‘ type=‘‘ class=‘logout‘ bindtap=‘logout‘>注销</button>
    </block>
    <block wx:if=‘{{!isMe}}‘>
      <block wx:if=‘{{isFollow}}‘>
        <button size=‘mini‘ type=‘‘ class=‘follow‘ data-followType=‘0‘ bindtap=‘followMe‘>已关注</button>
      </block>
        <block wx:if=‘{{!isFollow}}‘>
        <button size=‘mini‘ type=‘primary‘ class=‘follow‘ data-followType=‘1‘ bindtap=‘followMe‘>关注我</button>
        </block>
    </block>

    <view class=‘container-row‘>
      <label class=‘info-items‘>{{fansCounts}} 粉丝</label>
      <label class=‘info-items‘>{{followCounts}} 关注</label>
      <label class=‘info-items‘>{{receiveLikeCounts}} 获赞</label>
    </view>
  </view>

</view>

<view class="line"></view>

// pages/mine/mine.js
const app = getApp()
var videoUtils = require(‘../../utils/videoUtils.js‘)
Page({

  /**
   * 页面的初始数据
   */
  data: {
    faceImage: "../../resource/images/noneface.png",
    nickname: "昵称",
    fansCounts: 0,
    followCounts: 0,
    receiveLikeCounts: 0,
    isMe:true,
    isFollow:false,
    publisherId: ‘‘
  },
  /**
   * 用户注销
   */
  logout: function(e) {
    var user = app.getGlobalUserInfo();
    wx.showLoading({
      title: ‘正在注销中。。。‘
    });




    wx.request({
      url: app.serverUrl + "/logout?userId=" + user.id,
      method: "POST",
      header: {
        ‘content-type‘: ‘application/json‘ // 默认值
      },
      success: function(res) {
        console.log(res.data);
        var status = res.data.status;
        wx.hideLoading();
        if (status == 200) {
          wx.showToast({
            title: "用户注销成功~！",
            icon: ‘none‘,
            duration: 3000
          })
          // app.userInfo = null;
          wx.removeStorageSync("userInfo");
          wx.redirectTo({
            url: ‘../userRegister/userRegister‘,
          })

        } else if (status == 500) {
          wx.showToast({
            title: res.data.msg,
            icon: ‘none‘,
            duration: 3000
          })
        }
      }
    })
  },

  followMe: function (e) {
    var me = this;

    var user = app.getGlobalUserInfo();
    var userId = user.id;
    var publisherId = me.data.publisherId;

    var followType = e.currentTarget.dataset.followtype;



    // 1：关注 0：取消关注
    var url = ‘‘;
    if (followType == ‘1‘) {
      url = ‘/user/beyourfans?userId=‘ + publisherId + ‘&fanId=‘ + userId;
    } else {
      url = ‘/user/dontbeyourfans?userId=‘ + publisherId + ‘&fanId=‘ + userId;
    }

    wx.showLoading();
    wx.request({
      url: app.serverUrl + url,
      method: ‘POST‘,
      header: {
        ‘content-type‘: ‘application/json‘, // 默认值
        ‘headerUserId‘: user.id,
        ‘headerUserToken‘: user.userToken
      },
      success: function () {
        wx.hideLoading();
        if (followType == ‘1‘) {
          me.setData({
            isFollow: true,
            fansCounts: ++me.data.fansCounts
          })
        } else {
          me.setData({
            isFollow: false,
            fansCounts: --me.data.fansCounts
          })
        }
      }
    })
  },
  /**
   * 头像上传
   */
  uploadFace: function(e) {
    // var user = app.userInfo;
    var user = app.getGlobalUserInfo();
    var me = this;
    wx.chooseImage({
      count: 1, // 默认9
      sizeType: [‘compressed‘], // 可以指定是原图还是压缩图，默认二者都有
      sourceType: [‘album‘, ‘camera‘], // 可以指定来源是相册还是相机，默认二者都有
      success: function(res) {
        // 返回选定照片的本地文件路径列表，tempFilePath可以作为img标签的src属性显示图片
        var tempFilePaths = res.tempFilePaths
        if (tempFilePaths.length > 0) {
          console.log(tempFilePaths[0]);
          wx.uploadFile({
            url: app.serverUrl + "/user/uploadFace?userId=" + user.id, //仅为示例，非真实的接口地址
            filePath: tempFilePaths[0],
            name: ‘file‘,
            success: function(res) {
              var data = JSON.parse(res.data);
              console.log(data);
              wx.hideLoading();
              if (data.status == 200) {
                wx.showToast({
                  title: "用户上传成功~！",
                  icon: ‘none‘,
                  duration: 3000
                })
                me.setData({
                  faceUrl: app.serverUrl + data.data
                })


              } else if (data.status == 500) {
                wx.showToast({
                  title: data.msg,
                  icon: ‘none‘,
                  duration: 3000
                })
              }
            }
          })
        }

      }
    })
  },
  /**
   * 生命周期函数--监听页面加载
   */
  onLoad: function(params) {
    var me = this;

    var userInfo = app.getGlobalUserInfo();
    var publisherId = params.publisherId;
    var userId = userInfo.id;
    if (publisherId != null && publisherId != ‘‘ && publisherId!=undefined){
      userId = publisherId;
      me.setData({
        isMe:false,
        publisherId: publisherId,
      })
    }


    wx.showLoading({
      title: ‘正在获取用户信息。。。‘
    });
    wx.request({
      url: app.serverUrl + "/user/queryByUserId?userId=" + userId + "&fanId" + userInfo.id,
      method: "POST",
      header: {
        ‘content-type‘: ‘application/json‘, // 默认值
        ‘headerUserId‘: userInfo.id,
        ‘headerUserToken‘: userInfo.userToken
      },
      success: function(res) {
        console.log(res.data);
        var status = res.data.status;

        if (status == 200) {
          var userInfo = res.data.data;
          wx.hideLoading();
          var faceImage = me.data.faceUrl;
          if (userInfo.faceImage != null && userInfo.faceImage != ‘‘ && userInfo.faceImage != undefined) {
            faceImage = app.serverUrl + userInfo.faceImage;
          }

          me.setData({
            faceImage: faceImage,
            fansCounts: userInfo.fansCounts,
            followCounts: userInfo.followCounts,
            receiveLikeCounts: userInfo.receiveLikeCounts,
            nickname: userInfo.nickname,
            isFollow: userInfo.follow

          })
        } else if (status == 502){
          wx.showToast({
            title: res.data.msg,
            duration:3000,
            icon:‘none‘,
            complete:function(){
              wx.removeStorageSync("userInfo");

              wx.navigateTo({
                url: ‘../userLogin/userLogin‘,
              })
            }
          })

        }
      }
    })
  },

  uploadVideo: function(e) {
    videoUtils.uploadVideo();
  },

  /**
   * 生命周期函数--监听页面初次渲染完成
   */
  onReady: function() {

  },

  /**
   * 生命周期函数--监听页面显示
   */
  onShow: function() {

  },

  /**
   * 生命周期函数--监听页面隐藏
   */
  onHide: function() {

  },

  /**
   * 生命周期函数--监听页面卸载
   */
  onUnload: function() {

  },

  /**
   * 页面相关事件处理函数--监听用户下拉动作
   */
  onPullDownRefresh: function() {

  },

  /**
   * 页面上拉触底事件的处理函数
   */
  onReachBottom: function() {

  },

  /**
   * 用户点击右上角分享
   */
  onShareAppMessage: function() {

  }
})

PS：关注跟点赞类似也是操作后端的几张表来完成的，重点是前端需要判断状态，来进行显示对应的按钮，其实小程序把逻辑都给了前端。data里面的操作灵活的运用，业务逻辑的梳理。

「小程序JAVA实战」小程序的关注功能（65）