Using J2EE Security Correctly

Question

Regrettably my job consists of "working by the seat of my pants" on a continual basis. As such, I sometimes feel that although I can design a solution that "works", I often know there is a better design out there, its only my limitations of knowledge and experience that keeps me from it. With that said, here is my question:
I have been working on a system that entails multiple groups of users. Let's say Group A and Group B for argument sake. For security's sake (and by strict direction from my up-line managers) it was decided to store information for each group in its own set of tables (e.g. message tables would be split as Group1Messages Group2Messages) with entity beans for each (Group1MessageBean and Group2MessageBean) to enhance security.
Group1 would have full access to its respective beans and Group2 would have full access to its respective beans. Now here's the rub. There are some methods that Group2 will be able to access of Group1's bean. As the Group1 bean uses a database connection using it's own database user (e.g. a group1 database user), when Group2 is accessing Group1's bean, how can the database know which group is accessing/updating the information? Can the database know which group/role had accessed the bean for recording into the database? Can the bean use a different user/pwd authentication to the dbase depending on which group/role is accessing the bean for data?
If anyone has any suggestions here or resources to point me to I would greatly appreciate it.

Answer 1

Thanks for the answer. Indeed I had this </login-config>login-config> in code but after I made the correct changes I get the same error as before, j_security_check redirects to the error page as if the credentials would be wrong.
Another problem that I'd like to point is that I can't view any error message at console. How can I view in Console some errors from j_security_check?
Any other ideea will be helpful for me.
Tkans