Wow, is this topic still popping up!?
I finished my
SCJD about a year ago, and this was always a hot question then too. If you do a search on this forum for NIO you will get a lot of hits. In the past (and someone please correct me if this has changed in the last nine months), the response from Sun has been that you can use NIO as long as it does not explicitly forbid it in your instructions. The instructions you get from Sun as part of your assignment download are official, while the web site is not.
However, just to be safe... if you are planning on using NIO, you may want to email Sun and make sure.
“Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning.” - Rich Cook