I'm currently reading Robert Nystrom's book on Game Programming Patters. Free to read Web version on: http://gameprogrammingpatterns.com/contents.html
Very interesting for me, but while reading, and since I am doing my programming in Java, I found the examples occasionally a bit hard to read and understand. I wanted to look for some more concrete examples of game programming patterns written in Java.
A quick Google query already came up with some interesting posts:
Will look into it in more detail later.