What's the difference between TFTP and FTP? Does Java support TFTP?

TFTP stands for Trivial File Transfer Protocol - it is unrelated to FTP. TFTP is a simple protocol to implement file transfer via UDP. Unlike FTP, TFTP does not make use of any kind of user authentication.

For using TFTP in Java you could utilize the NetComponents classes from: http://www.savarese.org/oro/downloads/index.html