If you are starting with Neural Networks you should check out my online book on the subject. It contains over 300 pages of information on Neural Network Programming in Java. You can access it here.
G. Ruß, R. Kruse, P. Wagner, and M. Schneider. Advances in Data Mining (Proc. ICDM 2008), page 47--56. Berlin, Heidelberg, Springer Verlag, (July 2008)
A. Anand, M. Khosla, J. Singh, J. Zab, and Z. Zhang. Proceedings of the Twelfth ACM International Conference on Web Search and Data Mining, page 168--176. (2019)