ps: springboot combined with mybatisPlus and mysql to achieve, simple and easy to understand, one paste to use, see below for details↓

step:

1. Register a WeChat development platform account, create a mini program, and obtain the AppID and AppSecret of the mini program.
2. In the applet, guide the user to click the button to trigger WeChat login and get the code.
3. Send the code to the backend, and the backend obtains the user's openid and session_key through the code.
4. Use session_key to decrypt user data, and obtain user information, avatar, mobile phone number and other data.
5. Save user data in the database, or perform business processing in other ways.
Detailed code and steps:

1: Create a database

First, you need to create a MySQL database, name it wechat_mini_program, and create the following data tables:

CREATE TABLE `user` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `open_id` varchar(255) DEFAULT NULL COMMENT '用户唯一标识',
  `session_key` varchar(255) DEFAULT NULL COMMENT '会话密钥',
  `nickname` varchar(255) DEFAULT NULL COMMENT '用户昵称',
  `avatar_url` varchar(255) DEFAULT NULL COMMENT '用户头像',
  `gender` tinyint(1) DEFAULT NULL COMMENT '用户性别（0：未知，1：男性，2：女性）',
  `country` varchar(255) DEFAULT NULL COMMENT '用户所在国家',
  `province` varchar(255) DEFAULT NULL COMMENT '用户所在省份',
  `city` varchar(255) DEFAULT NULL COMMENT '用户所在城市',
  `phone_number` varchar(20) DEFAULT NULL COMMENT '用户手机号',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='用户表';

2: Introduce dependencies

Add the following dependencies to pom.xmlthe file :

<dependencies>
    <!-- Spring Boot 相关依赖 -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    
    <!-- MyBatis Plus 相关依赖 -->
    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-boot-starter</artifactId>
        <version>3.4.3.1</version>
    </dependency>
    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-generator</artifactId>
        <version>3.4.3.1</version>
    </dependency>
    <dependency>
        <groupId>org.apache.velocity</groupId>
        <artifactId>velocity-engine-core</artifactId>
        <version>2.2</version>
    </dependency>
    
    <!-- MySQL 驱动依赖 -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.27</version>
    </dependency>
    
    <!-- 微信小程序 SDK 依赖 -->
    <dependency>
        <groupId>com.github.binarywang</groupId>
        <artifactId>weixin-java-miniapp</artifactId>
        <version>3.8.0</version>
    </dependency>
</dependencies>

3: Configuration file

Add the following configuration to application.ymlthe file :

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/wechat_mini_program?useUnicode=true&characterEncoding=utf8mb4&autoReconnect=true&useSSL=false&serverTimezone=GMT%2B8
    username: root
    password: root
    driver-class-name: com.mysql.cj.jdbc.Driver
    
mybatis-plus:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.example.demo.entity
  global-config:
    db-config:
      id-type: auto
      table-prefix: mp_
      field-strategy: not_empty

#

4: Entity class

Create an Userentity class to represent user information:

package com.example.demo.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;

@Data
@TableName("user")
public class User {
    @TableId(value = "id", type = IdType.AUTO)
    private Long id;

    @TableField("open_id")
    private String openId;

    @TableField("session_key")
    private String sessionKey;

    @TableField("nickname")
    private String nickname;

    @TableField("avatar_url")
    private String avatarUrl;

    @TableField("gender")
    private Integer gender;

    @TableField("country")
    private String country;

    @TableField("province")
    private String province;

    @TableField("city")
    private String city;

    @TableField("phone_number")
    private String phoneNumber;
}

5:Mapper interface

Create an UserMapperinterface that defines useroperations on the table:

package com.example.demo.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.example.demo.entity.User;

public interface UserMapper extends BaseMapper<User> {
}

6: Service layer

Create an UserServiceinterface to define operations on user information:

package com.example.demo.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.example.demo.entity.User;

public interface UserService extends IService<User> {
    User getUserByOpenId(String openId);
    boolean saveOrUpdateUser(User user);
}

Create a UserServiceImplclass that implements UserServicethe interface:

package com.example.demo.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.example.demo.entity.User;
import com.example.demo.mapper.UserMapper;
import com.example.demo.service.UserService;
import org.springframework.stereotype.Service;

@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {
    @Override
    public User getUserByOpenId(String openId) {
        return this.baseMapper.selectOne(new LambdaQueryWrapper<User>().eq(User::getOpenId, openId));
    }

    @Override
    public boolean saveOrUpdateUser(User user) {
        return this.saveOrUpdate(user);
    }
}

7: Controller layer

Create a UserControllerclass to handle requests for user information:

package com.example.demo.controller;

import cn.binarywang.wx.miniapp.api.WxMaService;
import cn.binarywang.wx.miniapp.bean.WxMaJscode2SessionResult;
import com.example.demo.entity.User;
import com.example.demo.service.UserService;
import lombok.extern.slf4j.Slf4j;
import me.chanjar.weixin.common.error.WxErrorException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping("/user")
@Slf4j
public class UserController {
    @Autowired
    private WxMaService wxMaService;

    @Autowired
    private UserService userService;

    /**
     * 登录接口
     */
    @PostMapping("/login")
    public Result<Object> login(@RequestParam("code") String code, @RequestParam("encryptedData") String encryptedData,
                            @RequestParam("iv") String iv) {
    try {
        // 调用微信 API 获取用户的 openid 和 session_key
        WxMaJscode2SessionResult session = wxMaService.getUserService().getSessionInfo(code);
        String openid = session.getOpenid();

        // 调用微信 API 获取用户的手机号
        WxMaPhoneNumberInfo phoneInfo = wxMaService.getUserService().getPhoneNoInfo(session.getSessionKey(), encryptedData, iv);
        String phoneNumber = phoneInfo.getPhoneNumber();

        // 调用微信 API 获取用户的详细信息
        WxMaUserInfo userInfo = wxMaService.getUserService().getUserInfo(session.getSessionKey(), code);
        // 获取用户昵称
        String nickName = userInfo.getNickName();
        // 获取用户头像
        String avatarUrl = userInfo.getAvatarUrl();
        // 获取用户国家
        String country = userInfo.getCountry();
        // 获取用户省份
        String province = userInfo.getProvince();
        // 获取用户城市
        String city = userInfo.getCity();

        // 将用户信息保存到数据库中
        User user = userService.getByOpenId(openid);
        if (user == null) {
            user = new User();
            user.setOpenId(openid);
            user.setNickName(nickName);
            user.setAvatarUrl(avatarUrl);
            user.setCountry(country);
            user.setProvince(province);
            user.setCity(city);
            user.setPhoneNumber(phoneNumber);
            userService.add(user);
        } else {
            user.setNickName(nickName);
            user.setAvatarUrl(avatarUrl);
            user.setCountry(country);
            user.setProvince(province);
            user.setCity(city);
            user.setPhoneNumber(phoneNumber);
            userService.update(user);
        }

        // 返回用户信息
        Map<String, Object> data = new HashMap<>();
        data.put("openid", openid);
        data.put("nickName", nickName);
        data.put("avatarUrl", avatarUrl);
        data.put("country", country);
        data.put("province", province);
        data.put("city", city);
        data.put("phoneNumber", phoneNumber);
        return Result.success(data);
    } catch (WxErrorException e) {
        log.error("登录失败：" + e.getMessage(), e);
        return Result.error("登录失败：" + e.getMessage());
    }
/**
 * 更新用户信息接口
 */
@PostMapping("/update")
public String updateUserInfo(@RequestBody User user) {
    if (user == null || user.getOpenId() == null) {
        return "用户信息不能为空";
    }

    if (userService.saveOrUpdateUser(user)) {
        return "更新用户信息成功";
    } else {
        return "更新用户信息失败";
    }
}
}

8. Database table creation statement



创建 `user` 表的 SQL 语句如下：

```sql
CREATE TABLE `user` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键',
  `open_id` varchar(255) NOT NULL COMMENT '用户 openid',
  `session_key` varchar(255) DEFAULT NULL COMMENT '用户 session_key',
  `nickname` varchar(255) DEFAULT NULL COMMENT '用户昵称',
  `avatar_url` varchar(255) DEFAULT NULL COMMENT '用户头像 URL',
  `gender` int(11) DEFAULT NULL COMMENT '用户性别，0：未知，1：男性，2：女性',
  `country` varchar(255) DEFAULT NULL COMMENT '用户所在国家',
  `province` varchar(255) DEFAULT NULL COMMENT '用户所在省份',
  `city` varchar(255) DEFAULT NULL COMMENT '用户所在城市',
  `phone_number` varchar(20) DEFAULT NULL COMMENT '用户手机号',
  PRIMARY KEY (`id`),
  UNIQUE KEY `open_id_UNIQUE` (`open_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='用户表';

9: pom.xml configuration file

The following dependency packages need to be introduced:

<!-- mybatis-plus -->
<dependency>
    <groupId>com.baomidou.mybatisplus</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.4.3.1</version>
</dependency>

<!-- mysql -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.26</version>
</dependency>

<!-- weixin-java-miniapp -->
<dependency>
    <groupId>me.chanjar.weixin</groupId>
    <artifactId>weixin-java-miniapp</artifactId>
    <version>3.9.0</version>
</dependency>

10: Business explanation and calling process

This code implements the functions of applet user login and user information update.

The calling process is as follows:

The front end of the applet calls wx.loginthe method to obtaincode
The front-end of the applet will codepass to /user/loginthe interface of the back-end
The backend call wxMaService.getUserService().getSessionInfo(code)method gets session_keyandopenid
The backend openidqueries , and creates a new user if the user does not exist
The backend returns openidto the applet frontend
The front-end of the applet uses wx.getUserProfilethe method to obtain user information (such as nickname, avatar, etc.)
The front end of the applet transmits the user information openidtogether with /user/updatethe interface of the back end
The backend updates the user information and returns the update result to the frontend of the applet

over！

General: The above is the business process implemented by this code. For specific implementation, please refer to the code and comments given above.

It should be noted that when using this code, it is necessary to create an applet in the background of the applet and obtain appidand appsecret, and configure accordingly in the code. In addition, you need to apply for and obtain corresponding permissions on the WeChat open platform access_token. For specific operations, please refer to the official WeChat documentation.

ps: The code given above can be used as a basic implementation, and further development and optimization can be carried out on this basis.

(Detailed version) Java implements a small program to obtain WeChat login, user information, mobile phone number, and avatar