After quite a bit of interest (which surprised me, but is flattering), a pre-0.1 version of Classifier4J is available.
This includes the source and demo training and analyzing programs. No sample data is supplied, nor is any usage documentation at all. However, reasonably good JavaDoc is available.
The IClassifier interface and BayesianClassifier class are probably of the most interest.
As noted on the website, this is a pre release. Don’t expect it to be very useful if you aren’t a programmer!
I’m interested in all feedback - contact me on the mailing list, or via nick at nicklothian dot com