Java Swing

The File Chooser Package

Under javax.swing, you’ll find a package of helper classes for the JFileChooser. The javax.swing.filechooser package contains several classes for displaying and filtering files. (More classes are planned for this package, but they are currently located in the file chooser demo area in the examples/ directory of the Swing download package.)

The FileFilter Class

The FileFilter class can be used to create filters for JFileChooser dialogs. The class contains only two abstract methods, but default implementations based on filename extensions should become a standard part of the Swing package with the next release. It’s important to note that extensions are not the only way to judge a file’s fitness for a particular filter. The Mac filesystem, for example, can understand the creator of a file regardless of the file’s name. On Unix systems, you might write a filter to display only files that are readable by the current user.

Constructors

public FileFilter()

The FileFilter class receives this default constructor at compile time, it is not defined in the class itself.

Filter Methods

public abstract boolean accept(File f)

Returns true if the file f matches this filter.

public abstract String getDescription()

Returns a short description to appear in the filters pull-down on the chooser. An example would be “Java Source Code” for any .java files.

Figure 12.5 shows a file chooser with custom filters for multimedia file types.

Figure 12-5.  A custom set of filters for use ...