After the latest change in the MP3 licensing terms (no more free license
for MP3 softwares distributed as freeware), Sun Microsystems decided to
drop the MP3 support from its Java Media Framework.
Sun Microsystems drops MP3 support:
JMF 2.1.1b Available, 29-Aug-02:
JMF 2.1.1b is now available for download. This release fixes a few
critical bugs [...] and removes the MP3 encoder and decoder. If and when
licensing issues can be resolved, we plan to return MP3 functionality
back to JMF.