How to decompile and then recompile the jar with some changes?

Question

Java

There is a jar file (mod for minecraft) that I want to modify (remove some methods so that the laser does not work and you can craft a thermal centrifuge, which is prohibited on the server due to the laser). I decompiled via jd-gui and found the right class. I commented out the excess. But it is not possible to compile back (you need a whole folder). Maybe there is a program in which you can do everything at once (decompile, change, compile)? Or how?

Answer 1

In the development environment, include the source jar of the decompiled class as a library

Answer 2

Compile again as a full mod.
www.mikaellinusson.com/blog/2012/09/30/how-to-make...

Answer 3

If it is possible to change the classpath when the application starts, then save the changed class in a separate jar-nickname and put this jar-nickname in the classpath before the original one (which you passed).
The loader will find your class first, load it, and no longer load the original class.

Answer 4

if Applied Energistics is installed on the server, then you can craft everything in the ME terminal