private void setNoCacheHeaders(HttpServletResponse pResp) {
pResp.setHeader("Cache-Control", "no-cache");
pResp.setHeader("Pragma", "no-cache");
// Check for a date header and set it accordingly to the recommendations of
// RFC-2616 (http://tools.ietf.org/html/rfc2616#section-14.21)
//
// "To mark a response as "already expired," an origin server sends an
// Expires date that is equal to the Date header value. (See the rules
// for expiration calculations in section 13.2.4.)"
//
// See also #71
long now = System.currentTimeMillis();
pResp.setDateHeader("Date", now);
// 1h in the past since it seems, that some servlet set the date header on their
// own so that it cannot be guaranteed that these headers are really equals.
// It happened on Tomcat that Date: was finally set *before* Expires: in the final
// answers some times which seems to be an implementation peculiarity from Tomcat
pResp.setDateHeader("Expires", now - 3600000);
}
