Java IO.pdf - Nguyen Dang Binh

Example 13.7. JavaChooser
import java.io.*;
import javax.swing.*;
import javax.swing.filechooser.*;
import com.macfaq.swing.filechooser.*;
import com.macfaq.io.*;
public class JavaChooser {
}
public static void main(String[] args) {
}
JFileChooser fc = new JFileChooser();
fc.addChoosableFileFilter(new JavaFilter());
int result = fc.showOpenDialog(new JFrame());
if (result == JFileChooser.APPROVE_OPTION) {
try {
File f = fc.getSelectedFile();
if (f != null) {
FileInputStream fin = new FileInputStream(f);
StreamCopier.copy(fin, System.out);
fin.close();
}
}
catch (IOException e) {System.err.println(e);}
}
System.exit(0);
The JFileChooser class also a related accept() method:
public boolean accept(File f)
Java I/O
This passes the File object f through the file chooser's currently selected file filter. You'll
have little reason to call this method directly, and it's unclear why it's even public.
You do not need to construct a new subclass of FileFilter to create a new filter. Often it's
more convenient to encapsulate some algorithm in a subclass than parameterize the algorithm
in particular objects. For instance, Example 13.8 is an ExtensionFilter that extends
FileFilter. It's similar to the ExtensionFilenameFilter of Example 13.3. However, this
class also needs to store a description for each extension. Furthermore, the extensions are used
one at a time, not all at once. This reflects the difference between JFileChooser and
FileDialog.
Example 13.8. ExtensionFilter
package com.macfaq.swing.filechooser;
import java.io.*;
import javax.swing.filechooser.*;
import javax.swing.*;
321