Handling network errors during initial connection and ongoing use

Hey all,

I'm working on fixing an application that uses jdbc so it will provide
users with a better understanding of what is wrong when things go wrong.
However, I cannot find any information on elegant ways to handle the
'unreliable' part of tcp/ip.

Is there some common strategy to handle network errors during setup or
use of jdbc?

Specifically, I imagine all java applications using jdbc would have to
handle:
        during initial connection
                no network
                no dns
                host name unknown
                no answer on port
                answer on port not postgresql
                bad authentication
                        (wrong username/password if these are distinct)
                user doesn't have permissions to read database

        during ongoing use
                network failure
                server failure

Could anyone point me toward documents/topic which cover these issues?

Thank you,
adrian custer