Newbie question

Dear All!

Getting started with the JDBC programming i have some troubles:
1. Is there a kinda of solution to operate CIDR and other pgsql-specific
value types with PGSQL+Java (i know, that i can use ::text to get and
::cidr to set, but maybe there are some classes that extend Type class
that i did not find in the documentation)?
2. I found almost everything what i can get from Result/Database
metadata, but found no way to know the table name that that was
indicated in sql statemen during getting data.
3. Is there any way to know that data in the database was changed
(three-level application could do the trick, but i'm asking about simple
way - JTable->JSorter->JModel->postgresql without using RMI or whatever)

I'm kindly asking to give just an URL where i can find this type of
information?

Best regards,
Anton Nikiforov