Don't be frightened by the complexity of that last diagram. It's
not that bad.
You're going to implement JFrame anyway. That is the Swing component
that is your window.
You also need to implement the button.
The GUI editor in Forte/NetBeans will not only help you with the above,
it will also create and add the listener automatically! You'll only
need to do it by hand if you have to do some type of custom coding.
Here's how to do it.
First, from Forte'/NetBeans, choose New. A menu will appear, from
which you can choose JFrame. This creates an object of class
type JFrame. This is your 'window', so to speak.
The new JFrame object should appear in the GUI editor. If not, double
click on it in the Explorer window and it will.
Take a look at the example I made. You can right-click on the JComponent
(a button in this case), and follow the menu to the action listener.
Once you've created the ActionListener, Forte'/NetBeans takes you right
to the spot where you can enter your code.