微信小程序用code换取openid和session_key

public function get_openid_sessionkey(Request $request)
    {  
        //接收code
        $code = $request->post('code');
        //获取appid
        $appid = Env::get('APPID');
        //获取secret
        $secret = Env::get('APPSECRET');
        //请求链接
        $url = "https://api.weixin.qq.com/sns/jscode2session?appid=$appid&secret=$secret&js_code=$code&grant_type=authorization_code";
        //发送请求
        $info = httpGet($url);
        $json = json_decode($info);//对json数据解码
        $arr = get_object_vars($json);//返回一个数组。获取$json对象中的属性，组成一个数组
        return \sendResponse($arr);

    }