Group Development with JSP

Hi all,

I have a general question regarding development in Java/JSP.
Can any one advise me on methods and/or tools that would facilitate
development in a team environment, in which case each developer only has
access to a section of the code (in order to avoid "stealing of
codebase")?!?

Note that this is for small projects, so I am looking for solutions that are
not too complicated to implement, i.e. I do not have to hire a configuration
management expert to monitor each developer.

Thank you for your consideration,
Lamine