Spring web flow looses the extension ( as configured in the servlet mapping ) whenever redirects a request on session timeout.

We have a system configured to map the following pattern "*.swf" to be handled by Spring Web Flow servelt, this is, whenever the application gets a request like "whatever.swf" request, Spring Web Flow services it.

Whenever the HttpSession expires, and the user executes a request to the server, Spring Web Flow realizes that the session has expired and tries to redirect the user ( 302 ) to a URL that is composed in the excepcion handling code.

The problem arises at the mentioned URL composition, Spring Web Flow is not aware of the mapping and composes an URL that includes the name of the action requested without any execution parameter ( at that moment the execution context is already gone ), but also lacks of the extension configured in the servlet mapping.

The effect is that if there is no "/*" mapping in the application's web.xml the user get a 404.