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About This Short Course
Short Course
Exercises
This exercise produces an application rather than an applet. This application
should be run from the command line rather than from a page in a browser.
(Applets cannot do file I/O for security reasons.)
Open a Frame
with a list box and a text area. Using
routines provided for you, display the list of files in the current directory in
the list box. When the user double-clicks on an entry, display that file in the
text area.
Skeleton Code
Tasks
1. Create class DirectoryList as subclass of Frame.
In the constructor, set the size to 400 x 500, create the list box in the north
position, add the elements passed in to the constructor, and create a text area
in the center position.
2. Add the following code to DirectoryList so that you can shut
down the application window:
import java.awt.event.*;
...
// handle the WINDOW events here
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent event) {
setVisible(false);
dispose();
System.exit(0);
}
});
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3. Add an actionPerformed() method to handle selection of the list
elements. Upon selection (with a double-click operation), call displayFile()
with the filename selected.
Where help exists, the task numbers above are linked to the
step-by-step help page.
Solution Source
Demonstration
This program cannot be run as an applet as it uses file I/O. Please run
the solution from the command line as an application, or from an IDE window.
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