Java For Dummies Quick Reference

FileFilter Class

Package: javax.swing

This abstract class lets you create a class that can filter the files displayed by the JFileChooser class. For example, you can use this class to create a filter that will display only files with a certain filename extension in the file chooser. (For more information about file choosers and the JFileChooser class, see JFileChooser Class.)

For some reason, the Java designers gave this class the same name as an interface that’s in the java.io package, which is also frequently used in applications that work with files. As a result, you need to fully qualify this class when you extend it, like this:

class JavaFilter

extends javax.swing.filechooser.FileFilter

Methods

Method	Description
public boolean abstract accept(File f)	You must implement this method to return true if you want the file to be displayed in the chooser or false if you don’t want the file to be displayed.
public String abstract getDescription()	You must implement this method to return the description string that is displayed in the Files of Type drop-down list in the chooser dialog box.

The getDescription method simply returns the text displayed in the Files of Type drop-down list. You usually implement it with a single return statement that returns the description. Here’s an example:

public String getDescription()

{

return “Java files (*.java)”;

}

Here, ...