Learn and use the layout managers. And also nest JPanels. The main JPanel should use BorderLayout. A bottom JPanel should be placed into the main JPanel's BorderLayout.PAGE_END location. The bottom JPanel can also use BorderLayout, and then add the button can be added BorderLayout.LINE_END.
– Hovercraft Full Of EelsMar 27 '16 at 21:35
@HovercraftFullOfEels Doesn't the default `JPanel` (`JFrame.getContentPane()`) already have a `BorderLayout` by default?
– Olivier GrégoireMar 27 '16 at 21:40