[project training] wechat official account to obtain user openid

First , To facilitate the development and testing of official account , You can apply for a test number , The address is as follows

WeChat public platform

Push a message to a specified user , Usually need him openId, To get the user's openId, You can authorize callback through the web page of wechat official account （ With a user binding page , Wechat official account users can be connected with users of our own system ）

The above is the description of wechat development documents , As you can see, if we just want to do user binding , Then push the template message , that scope Just for snsapi_base

    @GetMapping("/getUserCode")
    public String  getUserCode(){
        String backUrl = "http://ip port /wx/getUserOpenId";
        String getOpenIdUrl = "https://open.weixin.qq.com/connect/oauth2/authorize?appid=APPID&redirect_uri="+ backUrl+"&response_type=code&scope=snsapi_base&state=STATE#wechat_redirect";
        getOpenIdUrl = getOpenIdUrl.replace("APPID",appid);
        return "redirect:" + getOpenIdUrl;
    }

    /**
     *  Get users openId
     * @return
     * @throws IOException
     */
    @GetMapping("/getUserOpenId")
    public  String getUserOpenId(HttpServletRequest request)throws IOException{
        // obtain code
        String code = request.getParameter("code");
        System.out.println("code:"+code);
        if(code== null){
            System.out.println("code It's empty ");
        }
        String openid = WechatUserUtil.exchangeCode2OpenId(code,appid,secret);
        return openid;
    }

 

    public static String exchangeCode2OpenId(String code,String appId,String appSecret) {
        String openid = "";
        try {
            //  Exchange for access_token  Which includes openid
            //  Through here code In exchange for a special webpage authorization access_token, And basic support access_token（ The access_token Used to call other interfaces ） Different .
            String URL = "https://api.weixin.qq.com/sns/oauth2/access_token?appid=APPID&secret=SECRET&code=CODE&grant_type=authorization_code"
                    .replace("APPID", appId).replace("SECRET", appSecret).replace("CODE", code);
            String jsonStr = HttpUtil.sendGet(URL);
            System.out.println("---------- Wechat exchange openid The result returned :{}----------");
            Gson gson = new Gson();
            WechatOpenId wechatOpenId = gson.fromJson(jsonStr, WechatOpenId.class);
            if (null != wechatOpenId) {
                openid = wechatOpenId.getOpenid();
            }
        } catch (Exception e) {
            System.out.println("---------- Wechat exchange openid Something is wrong :{}----------");
        }
        return openid;
    }