protected function redirect($url, $code = 302)
    {
        if (!headers_sent()) {
            if (SERVER_MODE === 'swoole' ) {
                $GLOBALS['__$response']->status($code);
            } else if ($code == 301) {
                header('HTTP/1.1 301 Moved Permanently');
            } else {
                header('HTTP/1.1 302 Found');
            }

            $this->setHeader("Location", $url);
            $this->stopRun();
        } else {
            echo '<html><head><meta charset="UTF-8" /><title></title></head><body>';
            echo '<script>window.location.href="'. $url .'";</script></body></html>';
            $this->stopRun();
        }
    }