An implementation of the DNS protocol in Java. dnsjava includes a set of classes that can be used within other programs and several user tools.
This is an excellent implementation of DNS in Java. I use it for name resolution in my library. The library looped through connecting to a server, and was noticeably faster when using dnsjava. The best part is that it complies with DNS standards even more than Java's implementation does, so I know I'm not degrading the internet.