org.apache.httpcomponents
            httpclient
            4.5.1
        
        
        
            commons-io
            commons-io
            2.6
        
        
        
            com.google.code.gson
            gson
            2.8.2
        

需要替换为公司的微信信息：

wx:
  open:
    # 微信开放平台 appid
    app_id: wxed9954c0********
    # 微信开放平台 appsecret
    app_secret: a7482517235173ddb40837**********
    # 微信开放平台 重定向url（****.****需要在微信开放平台配置）
    redirect_url: http://****.****/api/ucenter/wx/callback

/**
 * @author Symon
 * @version 1.0
 * @className WxApiController
 * @date 2021/1/8 14:56
 */
@Controller
@RequestMapping("/api/ucenter/wx")
@CrossOrigin
public class WxApiController {

    @Value("${wx.open.app_id}")
    private String WX_OPEN_APP_ID;

    @Value("${wx.open.appsecret}")
    private String WX_OPEN_APP_SECRET;

    @Value("${wx.open.redirect_url}")
    private String WX_OPEN_REDIRECT_URL;

    @Resource
    private MemberCenterService memberCenterService;

    // 1.生成二维码(官方文档第一步)
    @GetMapping("login")
    public String qrCode() throws Exception{
        String baseUrl = "https://open.weixin.qq.com/connect/qrconnect" +
                "?appid=%s" +
                "&redirect_uri=%s" +
                "&response_type=code" +
                "&scope=snsapi_login" +
                "&state=%s" +
                "#wechat_redirect";
        String state="abcd";
        //对回调路径进行编码
        String encodeUrl = URLEncoder.encode(WX_OPEN_REDIRECT_URL, "utf-8");
        //拼接字符串
        String qrCodeUrl = String.format(baseUrl, WX_OPEN_APP_ID, encodeUrl, state);
        return "redirect:"+qrCodeUrl;
    }


    @GetMapping("callback")
    public String callback(String code,String state) throws Exception{
        //a.通过code+appid+appsecret得到用户的access_token和openid(官方文档第二步)
        String baseAccessTokenUrl = "https://api.weixin.qq.com/sns/oauth2/access_token" +
                "?appid=%s" +
                "&secret=%s" +
                "&code=%s" +
                "&grant_type=authorization_code";
        //拼接字符串
        baseAccessTokenUrl = String.format(baseAccessTokenUrl, WX_OPEN_APP_ID, WX_OPEN_APP_SECRET, code);
        String retVal = HttpClientUtils.get(baseAccessTokenUrl);
        //把json字符串转换为Java对象
        Gson gson = new Gson();
        HashMap infoMap = gson.fromJson(retVal, HashMap.class);
        String accessToken =(String) infoMap.get("access_token");
        String openId =(String) infoMap.get("openid");
        
        //b.根据access_token和openid获取用户信息(官方文档第三步)
        String userInfoUrl = "https://api.weixin.qq.com/sns/userinfo" +
                "?access_token=%s" +
                "&openid=%s";
        //拼接字符串
        userInfoUrl = String.format(userInfoUrl, accessToken, openId);
        String userInfoJson = HttpClientUtils.get(userInfoUrl);
        HashMap userInfoMap = gson.fromJson(userInfoJson, HashMap.class);
        String nickName =(String) userInfoMap.get("nickname");
        String headImgUrl =(String) userInfoMap.get("headimgurl");
        // ......

        //c.拿到用户的个人信息 需要存储起来 存之前先判断该用户是否已经在数据库中有了
        MemberCenter existMember=memberCenterService.queryUserByOpenId(openId);
        if(existMember==null){
            existMember = new MemberCenter();
            existMember.setOpenid(openId);
            existMember.setNickname(nickName);
            existMember.setAvatar(headImgUrl);
            memberCenterService.save(existMember);
        }
        //d.返回一个token给前端
        String token = JwtUtils.geneJsonWebToken(existMember);
        return "redirect:http://127.0.0.1:3000?token="+token;
    }
}

参数说明：

// 1.生成二维码(官方文档第一步)

// a.通过code+appid+appsecret得到用户的access_token和openid(官方文档第二步)

// b.根据access_token和openid获取用户信息(官方文档第三步)

获取用户个人信息（UnionID机制）

请求说明

http请求方式: GET
https://api.weixin.qq.com/sns/userinfo?access_token=ACCESS_TOKEN&openid=OPENID

参数说明

返回说明

正确的Json返回结果：

{
"openid":"OPENID",
"nickname":"NICKNAME",
"sex":1,
"province":"PROVINCE",
"city":"CITY",
"country":"COUNTRY",
"headimgurl": "https://thirdwx.qlogo.cn/mmopen/g3MonUZtNHkdmzicIlibx6iaFqAc56vxLSUfpb6n5WKSYVY0ChQKkiaJSgQ1dZuTOgvLLrhJbERQQ4eMsv84eavHiaiceqxibJxCfHe/0",
"privilege":[
"PRIVILEGE1",
"PRIVILEGE2"
],
"unionid": " o6_bmasdasdsad6_2sgVt7hMZOPfL"

}

原文：https://www.cnblogs.com/ilusymon/p/14252955.html