Design Patterns Java™ Workbook

Chapter 4. Facade

The javax.swing package contains JOptionPane, a class that "makes it easy to pop up a
standard dialog box," according to the class comment.

For example, the following code displays and redisplays a dialog until the user clicks the Yes
button (see Figure 4.5):

package com.oozinoz.applications;
import javax.swing.*;
public class ShowOptionPane
{
public static void main(String[] args)
{
int option;
do
{
option =
JOptionPane.showConfirmDialog(
null,
"Had enough?",
" A Stubborn Dialog",
JOptionPane.YES_NO_OPTION);
}
while (option == JOptionPane.NO_OPTION);
}
}

Figure 4.5. The JOptionPane class makes it easy to display dialogs such as this one.

CHALLENGE 4.3

The JOptionPane does in fact make it easy to display a dialog. State whether this

class is a facade, a utility, or a demo, and justify your answer.

CHALLENGE 4.4

Few facades appear in the Java class libraries. Why is that?