Problem with getServletContext().getRequestDispatcher(....).forward()

Question

We are using the latest SJSWS 7.0U8, but have the following problem:
During GET requests, getServletContext().getRequestDispatcher(....).forward(req,resp) works fine. But if the client issues a HEAD request, the servlet crashes with a ClassCastException. This bug was known for older versions of Tomcat but is fixed there. Maybe the fix could be applied to SJSWS internal catilina engine, too?
Are there any idea to walk around that problem, but let HEAD request still produce the correct headers for such a request(file size,...)?
[17/Feb/2010:19:39:28] failure ( 9211): for host a.b.c.d trying to HEAD /xxxxx, service-j2ee reports: StandardWrapperValve[xxx]: PWC1406: Servlet.service() for servlet xxx threw exception
java.lang.ClassCastExceptionNo stack trace is logged, but some time in the past i printed a complete stack trace in a catch block and the reason for that is:
The default HEAD handler in the servlet uses NoBodyResponse to wrap the original ServletResponse. The code of forward() later tries to cast this response object to a standard HttpServetResponse, what it is not. Tomcat/Jetty have a fix for it (I do not know the bug number).
This happens now very often, as newer browsers like Chrome sometimes issue HEAD requests during page display (not sure why).

Answer 1

Some more infos about the problem (the root cause is in the HttServlet.NoBodyResponse implementation in the Servlet Spec):
[https://issues.apache.org/bugzilla/show_bug.cgi?id=22290]
Some investigations about this (NoBodyResponse should extend HttpServletResponseWrapper and not Object): [http://closingbraces.net/2006/12/31/httpservletissues/], [http://closingbraces.net/2007/01/29/httpservletissuesfollowup/]
That is a similar stack trace I get (I get it with catilina classes, but same root cause): [http://markmail.org/message/pbdcbav6y2vlzbfc] or ClassCastException in weblogic.servlet.internal.ServletResponseImpl
Edited by: thetaphi on Feb 17, 2010 11:34 AM