Java Loading/Progress Bar

I have a JPanel, and I'd like to add a Progress Bar to it. I've never used Progress Bar before, and I've searched around the web and found some links, but still haven't gotten what I wanted.

I want a progress bar that I can specify the width, the height, and that has a percentage in the middle of it. And, I'd like to be able to set that percentage whenever I want.

Oracle has a very detailed page about how to use Swing's progress bar. Check it out you'll find all you need, including .java files with coded examples: it is called How to Use Progress Bars.