Defining local IP address when opening connections to database

Hi,

I've got a problem when using the PostgreSQL JDBC driver to open a
connection to a database (not using SSL). The server on which I'm using
the driver has several IPs configured, but I would like to use a certain
IP (since only for that IP the firewalls have been set-up to allow the
connection to the database). Looking at the documentation I couldn't
find a way to define this local IP.
Have I missed something? If not, would it be possible to add this
feature of defining the local IP when setting up a connection?

Cheers,

Michael