I have a MyFile.jar file. I use JD-GUI to decompile it and used its "Save All Sources" options to save the files to a .zip file. Now extracted the .zip file and edited a .java file.
the folder structure after extracting .zip file is like this
_____ META-INF(folder)
source(folder) -------|
------com(folder)-->example--->App---> all .java files
now how do i recompile it back to .jar file ??
As mentioned in your question, you have decompiled the class files to java files and have done necessary modifications.
Hope you have imported that as a project in eclipse. Export the same as jar. point to be noted is that you should know the dependencies for building the project