filechooserfilter.java

由于想一次上传成功 所以将二个教程打包成了一个 这些例子几乎包含了所有java的框架集合

import java.io.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;

/*
<APPLET
    CODE = filechooserfilter.class
    WIDTH = 200
    HEIGHT = 200 >
</APPLET>
*/

public class filechooserfilter extends JFrame implements ActionListener
{
    JFileChooser jfilechooser = new JFileChooser();
    JButton jbutton = new JButton("Display file chooser");
    JTextField jtextfield = new JTextField(20);

    public filechooserfilter() 
    {
        super(); 
        
        Container contentPane = getContentPane();

        contentPane.setLayout(new FlowLayout());

        contentPane.add(jbutton);        
        contentPane.add(jtextfield);        

        jbutton.addActionListener(this);
         
        jfilechooser.addChoosableFileFilter(new filter1());
        jfilechooser.addChoosableFileFilter(new filter2());
    }

    public void actionPerformed(ActionEvent e) 
    {
        int result = jfilechooser.showOpenDialog(null);

        if(result == JFileChooser.APPROVE_OPTION) {
            jtextfield.setText("You selected " + 
                jfilechooser.getSelectedFile().getPath());
        }
    }

    public static void main(String a[]) 
    {
        JFrame jframe = new filechooserfilter();

        jframe.setBounds(200, 200, 300, 300);

        jframe.setVisible(true);

        jframe.setDefaultCloseOperation(
            WindowConstants.DISPOSE_ON_CLOSE);

        jframe.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) 
            {
                System.exit(0);
            }
        });
    }
}

class filter1 extends javax.swing.filechooser.FileFilter 
{
    public boolean accept(File fileobj) 
    {
        String extension = "";

        if(fileobj.getPath().lastIndexOf('.') > 0)
            extension = fileobj.getPath().substring(
                fileobj.getPath().lastIndexOf('.') 
                + 1).toLowerCase();

        if(extension != "")
            return extension.equals("gif");
        else
            return fileobj.isDirectory();
    }

    public String getDescription() 
    {
        return "Gif Files (*.gif)";
    }
}

class filter2 extends javax.swing.filechooser.FileFilter 
{
    public boolean accept(File fileobj) 
    {
        String extension = "";

        if(fileobj.getPath().lastIndexOf('.') > 0)
            extension = fileobj.getPath().substring(
                fileobj.getPath().lastIndexOf('.') 
                + 1).toLowerCase();

        if(extension != "")
            return extension.equals("java");
        else
            return fileobj.isDirectory();
    }

    public String getDescription() 
    {
        return "Java Files (*.java)";
    }
}