When I took it in 2002, it was C++ at the time. I think they switched to Java a year or two later.
You're close. I took the AP test the last year it was C++. I was also taking Java with the same instructor, same room, the next period, so I kind of had the best and worst of both worlds. But the instructor was top notch and is regionally well known - I'm very sure he was the primary factor in nearly all of his AP students both passing the AP test and having a job in the industry. Those two classes got me through my first two years of college and put me in a unique position for learning low/high level languages ever since.
That was 2003 when even the standard library was not nearly as defined and the boost/twisted libraries were still in their infancy. 2004 was the first year the AP comp. sci test was in Java and, IIRC, it was Java 1.4 when it was still reasonably fresh. These days I use primary Java and stumble through a handful of dynamic languages on an every day basis, but C++ still holds a special place in my heart - it's a shame I can't realistically use it in our production code; I really miss it.