Servlet automatic invokation (or ISAPI filter concept)

Hi,
Does the Jigsaw server support filtering requests like IIS - ISAPI
filters?
I wonder if there is any way (not servlet alias) to invoke a servlet
when a request to the server is made without the need to define the
servlet's URL(this will allow to run the servlet without specifically
include the servlet name or URL - e.g. write page counter servlet or
anything
else which will run any time a user is entering to the server - no
matter which URL
on the server the user request).
thanks,
Ruby