Refreshing a Window in Java

I'm using the JFreeChart library to draw charts in Java, blahblah...

I need the chart to draw on button click, how do I refresh the window without having to use setVisible(false) then setVisible(true)?

repaint() doesn't do shit.

>>7
Doesn't stop JVM's GC from being slow as fuck
That, and the horrible syntax, and the horrible API, and how it shoves OOP's in its shittiest down your throat.