qq登录，使用get_user_info接口，返回的json无法解析的解决办法

	$url = "https://graph.qq.com/user/get_user_info?access_token={$accessToken}&oauth_consumer_key={$appKey}&openid={$openId}&format=json";
	$pos = strpos($json,'}');
        $json=substr($json, 0, $pos + 1); //去掉}后面的结束字符
	$userInfo = json_decode($json);