Packfile API

Does anyone know an easy to use packfile API for Java?

Just a tool to pack a folder and all subfolders with files into a packfile, and then an easy API to seek in there.
I mean I wouldnt like to have to change all my file accesses after that, just the path… to a virtual location which is the packfile…
If possible =3

Intriguing… Google found this:

https://truezip.java.net/kick-start/tutorial.html