Maybe interesting to you
1- 19th Training Part of Java RE from ricardonarvaja
Of course, the language of the articles is not English (that is why I have not read it myself)
Code:
http://ricardonarvaja.info/WEB/OTROS/JAVA/
2- Reverse Engineering for Beginners
Topics discussed: x86/x64, ARM/ARM64, MIPS,
Java/JVM.
Code:
https://beginners.re/
3- Covert Java: Techniques for Decompiling, Patching, and Reverse Engineering Paperback
book info (amazon)
Code:
https://ketab.io/book/561583/