Java Programming

Hi, I've searched for info on how to do this but havent found anythin, or if its possible, other than actually taking the DB down. When our server starts it pulls data from the DB and stores it in the cache. Now when the server is running if the database goes down then comes back up and be try and refresh a cache it still see's the DB as being down, even though at this stage it is back. I need to reconnect but am having problems at the minute. Dont fancy asking for the DB to be brought down everytime I try something new!

Any help would be much appreciated.

Thanks