Hand Edit A Jar to Change Package Names

Question

I have a jar file from an external source. All of the classes in the jar are in the com.xyz package.

I would like to move all of classes to the com.xyzold package.

Is this is simple as unzipping the jar, renaming the xzy folder to xyzold, and rezipping it, or do I need to modify each class file as well?

---

Here's my solution, using Jar Jar Links

java -jar jarjar-1.4.jar process rules.txt google-collections-1.0.jar google-collections-old-1.0.jar 

And here's the contents of my rules.txt file:

rule com.google.** com.googleold.@1 

Answer 1

You can use Jar Jar Links to achieve that. Also you don't need the source code of the classes you'd like to modify, as the program does it on the bytecode level (ie. it modifies the .class files directly.)