As far as I am aware, Jeff Heaton is perhaps one of the initial implementers of Machine learning in Java. His company Heaton research provides Encog framework that has almost everything – Neural networks, Clustering, Singular value decomposition and what not. Jeff’s approach is to give you the idea without making the mathematics heavy. This book is part of the 3 series in AI. All three are easy to read. His explanation on Genetic algorithms, along with pseudo code implementations is a great attraction.