response.sendError(response.SC_NOT_FOUND);
response.sendError(HttpServletResponse.SC_NOT_FOUND);
    public void deliver(String identifier, HttpServletResponse response,                        Device out) throws IOException {        ExternalizedResource extInfo = getExternalizedResource(identifier);                if ( extInfo == null ) {            logger.warning("identifier " + identifier + " not found");            response.sendError(response.SC_NOT_FOUND);            return;        }        deliver(extInfo, response, out);    }