为什么获取不到到unionid？公众号也关注了，scope也是userinfo不是base。
String url = "https://api.weixin.qq.com/sns/oauth2/access_token?appid="+this.wxAppid+"&secret="+
this.wxSecret+"&code="+request.getCode()+"&grant_type=authorization_code";
String url = "https://api.weixin.qq.com/sns/userinfo?access_token="+token+"&openid="+openid+"&lang=zh_CN";
