I took the AP exam quite a while ago. (11 years now, yikes) My school also didn't really have an AP class, but a few of us wrote the test, and it was extremely easy for all of us as I remember. (though it was not java back then)
The university I went to (Alberta) let me skip a boring intro cs course (and sit through the second boring intro cs course ;) ) because of it, so it was worth it, though I didn't get any credits.
It's nice to know others have had success in the past with similar endeavors. I also ordered a book with that gift card to help so hopefully I can get a roll on with learning and earn some college credit if possible :)
C++: Where your friends have access to your private members