Thomas, But you're using Struts 1.3.8 right? The interceptor solution is for Struts 2.
I once thought of adding an "internal" attribute to my Struts actions. If the action had this property set through <set-property>, then the Controller would not allow the action to be executed directly (i.e., through the address bar). The only way it could be accessed was if the action was internally forwarded or included from a request. Does this sound similar to you? Paul