private static String getServerName(Request request) {
        try {
            return Request.getServerName(request);
        } catch (IllegalArgumentException e) {
            /*
             * getServerName() may throw IllegalArgumentException for invalid requests where request line contains a URI with relative path.
             * Jetty correctly responds with '400 Bad Request' prior to invoking our request log implementation.
             */
            logger.log(Level.FINE, e, () -> "Fallback to 'Host' header");
            return request.getHeaders().get("Host");
        }
    }
Implements the request accessing logging for Jetty.

@author Oyvind Bakksjo
@author bjorncs
container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/AccessLogRequestLog.java