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