problems record

public static URL serverURL(HttpServletRequest request) throws MalformedURLException {
        StringBuffer url = new StringBuffer();
        String scheme = request.getScheme();
        int port = request.getServerPort();
        if (port < 0)
            port = 80;
        url.append(scheme);
        url.append("://");
        url.append(request.getServerName());
        if (scheme.equals("http") && port != 80 || scheme.equals("https") && port != 443) {
            url.append(‘:‘);
            url.append(port);
        }
        return new URL(url.toString());
    }