Hi all,
how to access distribution list's contacts through java applications? can we access by using jsp,servlets alone or need to use any other api's like javamail api or third party api's like "J-Integra" ?

sll my need is for a web portal -> userv access validation. only particular accounts or team users are allowed to access that portal. i need this to be done in java technology. also, i dont want to use seperate databases and login processing actions. the process can be,

1. to get system login user name credentials.
2. once i get that i need to validate that user to exist in a particular distribution list or user-group.

how to do this?
Please help me out. whether this is possible, if so, how?
if it is not possible, then reason please? so that i can document and proceed in a formal fashion.