The other day I wanted to customize methods in a foreign Java library, so I was looking for a suitable tool. I looked a lot into bytecode editors and bytecode. But finally I ended up with Recaf and I am absolutely thrilled: https://github.com/Col-E/Recaf
The tool can be found at the following address: https://github.com/Col-E/Recaf/releases. Decompiling, recompiling and manipulating libraries is child’s play with Recaf! It’s best to try it out right away.
$ java -jar recaf-2.18.2-J8-jar-with-dependencies.jar