Swing GUI calling C++... Is this efficient?

Im building a Swing GUI that will parse multi table tournament summaries, have a hand replayer, and also pokerstove-esque EV calculations via hand ranges. I know basic-intermediate C++ and Im completely new to Java. On advice from my cousin, a senior programmer, and all around nerdy badass, Im attacking this from a "Swing GUI that will call on C++ for calculations" angle.

However, in trying to learn Swing, Im finding out Im going to have to become at least as good at Java as I am at C++. So, Im wondering if I couldnt build it all in Java, as a more efficient method.

Thanks for the input... and as for the cryptic title, I only wanted people to look at it who would understand my question.
haha