Deep Learning is the hottest topic in all of data science right now. Adam Gibson, cofounder of Blix.io, has created an open source deep learning library for Java named DeepLearning4j. For those curious, DeepLearning4j is open sourced on github.
Below is a video of Adam introducing deep learning and DeepLearning4j. Also, if you are interested in learning more about deep learning. Here are a couple more very help links.