Tomcat SOAP with Realm authentication

[john]

I have setup tomcat 5 to use a jdbc realm to authenticate the username
and password for each soap request and this works great. Is it possible
to restrict access to some soap methods to a user with a particular
role ?

At the moment any authenticated soap request can call any of the soap
methods described in my deployment descriptor but I want to define
different methods available to different users based on the role the
user is assigned via the jdbc realm authentication.

thanks,

John.