More on the BEA 8.1 Servlet Filter & RequestDispatcher issue
After doing some more research, it seems that the BEA developers found the Servlet 2.3 specification to be "ambigous", and decided to create an implementation that executes filters on both incoming http requests from cleients, and on request dispatcher requests.
This issue is resolved in the Servlet 2.4 spec. and there is a "dispatcher" element in the "filter" tag in web.xml
The valid values are:
- REQUEST: (default) only when the request comes directly from the client
- FORWARD
- INCLUDE
Please notice that the default behaviour has changed. Upgrading to Weblogic 9.2 or or doing a manual check in the filter for repeated requests solves the problem.