OS X has, since 10.7 Lion, a "native" way for apps to go fullscreen. It is represented by two arrows at the top left of the window.
Using this kind of fullscreen has the advantage that the normal OS X shortcuts to switch windows still work, and when the new OS X 10.9 is out, it will work even better, allowing users to have other windows on a second monitor still visible.

I'm sure someone around the office is using OS X so they should be able to tell you how it should work

Java applications can use this native fullscreen as described in this SO thread: http://stackoverflow.com/questions/6873568/fullscreen-feature-for-java-apps-on-osx-lion.

Applications that provide this feel more "at home" on the OS X platform and have, imho, a better user experience (especially since your current fullscreen mode disables the default osx shortcuts and blacks out other monitors), so please consider doing this