The "REST With Spring" Course:
Design patterns implemented in Java
All Algorithms implemented in Java
Everything you need to know to get the job.
FizzBuzz Enterprise Edition is a no-nonsense implementation of FizzBuzz made by serious businessmen for serious business purposes.
MIT Deep Learning Book in PDF format (complete and parts) by Ian Goodfellow, Yoshua Bengio and Aaron Courville
Modern Java - A Guide to Java 8
LeetCode of algorithms with java solution(updating).
From Java To Kotlin - Your Cheat Sheet For Java To Kotlin