I've Goog'd but I can't find any third party library that will let you create a jar file programmatically. I amazed that even Apache commons-io doesn't seem to have such functionality.

I'd rather not implement it myself as the API is rather low level. Are there any 3rd party libraries out there that will do the job?

Edit: I meant programmatically in Java. I don't want to drop out to the shell and I don't want to work with java.io.*.