Question

I started off with a .jar file that I unzipped. I need to change a few lines of code in just ONE of the classes contained in the contents of that jar file. I went about this as follows:

1) opened the class in Java Decompiler to view the source.

2) copied source to a new text file and saved with “.java” extension.

3) in command line I went to jdk folder and executed javac Classname.java to recompile.

However this class code imports some dependencies so the recompile failed. I have the dependencies, they were part of the original jar file contents but they are all compiled .class files and spread across several folders…

Is it possible to re-compile this class successfully? Is there command line code to include dependencies?

Answer 1

Yes, use the -classpath option.

javac -classpath original.jar Modified.java

Then, you can remove the old class from the jar file and insert the new one. There isn’t a simple way to do this via command line, so I recommend an archive application such as WinRAR or 7-zip.