public void process(final HttpResponse response, final HttpContext context) throws HttpException, IOException { if (response == null) { throw new IllegalArgumentException("HTTP response may not be null."); } int status = response.getStatusLine().getStatusCode(); if ((status >= HttpStatus.SC_OK) && !response.containsHeader(HTTP.DATE_HEADER)) { String httpdate = DATE_GENERATOR.getCurrentDate(); response.setHeader(HTTP.DATE_HEADER, httpdate); } }