SpringBoot置换微信小程序的openId和unionId

注意：获取到unionid需要绑定到公众平台否则获取不到

直接代码

1.第一步在application.yml中添加必要配置

#配置微信的信息
wx:
  appId: ---------
  appSecret: ------------
  grantType: authorization_code
  requestUrl: https://api.weixin.qq.com/sns/jscode2session
wxToken:
  url: https://api.weixin.qq.com/sns/oauth2/access_token
wxUnionId:
  url: https://api.weixin.qq.com/sns/userinfo

2.创建compoent将配置文件的属性绑定到方法中

package com.landimc.compoent;

import com.alibaba.fastjson.JSONObject;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.landimc.tools.AES;
import com.landimc.tools.HttpUtils;
import org.springframework.beans.factory.annotation.ParameterResolutionDelegate;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import java.util.HashMap;
import java.util.Map;

/**
 * 微信工具
 *
 * @auther Yang
 * @createTime 9:20
 * @Version 1.0
 */
@Component
public class WxConfig {

    @Value("${wx.appId}")
    private String appId;

    @Value("${backedWx.appId}")
    private String backedAppId;

    @Value("${backedWx.AppSecret}")
    private String backedAppSecret;

    @Value("${wx.appSecret}")
    private String appSecret;

    @Value("${wx.grantType}")
    private String grantType;

    @Value("${wx.requestUrl}")
    private String requestUrl;

    @Value("${wxToken.url}")
    private String tokenUrl;

    @Value("${wxUnionId.url}")
    private String unionUrl;

    /*获取用户的openid*/
    @SuppressWarnings("unchecked")
    public Map<String, Object> getSessionByCode(String code) {
        Map<String, Object> json = null;
        try {
            String url = requestUrl + "?appid=" + appId + "&secret=" + appSecret + "&js_code=" + code + "&grant_type=" + grantType;
            // 发送请求
            String data = HttpUtils.get(url);
            ObjectMapper mapper = new ObjectMapper();
            json = mapper.readValue(data, Map.class);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return json;
    }
/*获取用户的access_token*/
    @SuppressWarnings("unchecked")
    public Map<String, Object> getUserAccessToken(String code) {
        Map<String, Object> json = null;
        try {
            String url = tokenUrl + "?appid=" + appId + "&secret=" + appSecret + "&code=" + code + "&grant_type=authorization_code";
            // 发送请求
            System.out.println(url);
            String data = HttpUtils.get(url);
            ObjectMapper mapper = new ObjectMapper();
            json = mapper.readValue(data, Map.class);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return json;
    }

    /*获取用户的unionId*/
    @SuppressWarnings("unchecked")
    public Map<String, Object> getUnionId(String token, String openId) throws Exception {
        Map<String, Object> json = null;
        try {
            String url = unionUrl + "?access_token=" + token + "&openid=" + openId;
            // 发送请求
            String data = HttpUtils.get(url);
            ObjectMapper mapper = new ObjectMapper();
            json = mapper.readValue(data, Map.class);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return json;
    }

}

3.controller层

  　　/**
     * 根据微信code获取微信信息
     *
     * @param code 微信临时code
     * @return
     */
    @ApiOperation(value = "微信的code置换微信openid和unionid - 管理员用的")
    @ResponseBody
    @RequestMapping(value = "/backedUserLogin", method = {RequestMethod.GET, RequestMethod.POST})
    public String backedUserLogin(@RequestParam(value = "code") String code, @RequestParam(value = "iv") String iv, @RequestParam(value = "encryptedData") String encryptedData) {
        logger.info("根据微信code获取微信信息--后台用户请求");
        BackResult backResult = new BackResult();
        BizResult bizResult = new BizResult();
        try {
            //获取用户的openId和用于的session_key
            Map<String, Object> map = wxConfig.getBackedSessionByCode(code);
            //判断置换的openid是否正确
            if (map.isEmpty()) {
                bizResult.setCode(BizSuccessType.UNSUCCESS);
                bizResult.setMsg("获取用户微信信息错误！");
                bizResult.setDevMsg("微信的code错误！");
            } else {
                String session_key = map.get("session_key").toString();
                String openId = map.get("openid").toString();
                String decrypt = AES.decrypt(session_key, iv, encryptedData);
                bizResult.setCode(BizSuccessType.SUCCESS);
                bizResult.setMsg("获取用户微信信息成功！");
                //将json字符串转换为JSON对象
                JSONObject jsonObject = JSON.parseObject(decrypt);
                backResult.setData(jsonObject);
                //生成token
                String token = MD5.getMd5(UUID.randomUUID().toString().replace("-", ""), 32);
            }
        } catch (Exception ex) {
            ex.printStackTrace();
            bizResult.setCode(BizSuccessType.BIZAPPEX);
            bizResult.setMsg("获取用户微信信息失败！");
            bizResult.setDevMsg(ex.getMessage());
            ex.printStackTrace();
        }
        backResult.setBizResult(bizResult);
        return JSON.toJSONString(backResult);
    }

前端记得传递三个参数 都可以从微信那边获取到 这个自己看看微信登录的方法

code  iv  encryptedData