Packaging platform specific libs in one jar

The project I'm working on will likely be used on all 3 platforms, Windows, Linux, and OS X. Will I create issues by packaging all 3 sikulixlibs*.jar files (name clashes, etc) in the same jar file? I'm trying to determine if I can build once, run anywhere, or if I need to distribute platform specific jar files to the machines I'll be using.

Thanks in advance,

--Mike