My environment: JBoss 2.4.4-Tomcat-4.0.1. (Embedded)

For my application, I need to store files temporarily in Tomcat's 'docBase' directory. I could do this by either (a) specifying the directory, so my app knows where it is, or (b) finding out where it is after deployment so I can use it.
I've been unable to do (a) because in my JBoss/Tomcat combo nothing I've tried has worked, and it's not clear if or how you can specify the information. Changes to the mbean section of jboss.jcml are parsed but don't seem to have any effect. No success with (b) because I can't figure out how to access the docBase setting from within a request context.

Any ideas/suggestions/pointers would be really appreciated.