https://docs.oracle.com/javase/jp/10/tools/javap.htm
javap
You use the javap command to disassemble one or more class files.
https://javarevisited.blogspot.com/2013/01/how-to-decompile-class-file-in-java-eclipse-javap-example.html?showComment=1772112326746
How to decompile class file in Java and Eclipse - Javap command example
Sometime you need source by decompile class file and thankfully there are lot of tools available including JAD plugin for Eclipse IDE or javap command line...
how to