Until now, the programs you have been creating have perhaps not been what you may instinctively think of as a useful program. You can't expect a user to be prepared to enter all the input and get all the output on the command line. A more practical program would be window-based, with one or more windows that provide the interface between the user and the application. These windows, and the environment that the user interacts with, are known as the graphical user interface (GUI).
In this chapter you'll investigate how to create a window for a Java application, and you'll take a first look at some of the components you can assemble to create a graphical user interface in Java.
You will learn:
How you create and display a resizable window
What components and containers are
How you can add components to a window
How you can control the layout of components
How you create a menu bar and menus for a window
What a menu shortcut is and how you can add a shortcut for a menu item
What the restrictions on the capabilities of an applet are
How to convert an application into an applet