 <p><a href="http://www.codetrails.com/blog/introduction-bayesian-networks-jayes" rel="nofollow">Jayes</a> is a Java library for Bayesian networks and the inference in such networks. At the moment, there is no learning component included. (We can, however, recommend the <a href="http://mahout.apache.org/" rel="nofollow">Apache Mahout</a> library.)</p>