/**
* 产生28位 openid
* @param $clientID
* @param $user_id 用户在服务端登录id
* @return string
*/
protected function generateOpenID($clientID, $user_id)
{
$str = substr($clientID, 0, 6);
$str .= substr(md5($user_id, false), 0, 15);
$encryptionUtil = new Jwt();
$str = $encryptionUtil->urlSafeB64Encode($str);
return $str;
}
