java 中簡單的儲存對話方塊

import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;

import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.filechooser.FileNameExtensionFilter;

public class FileChooserFrame extends JFrame {

 private JPanel panel = null;
 
 private JTextArea area = null;
 
 public FileChooserFrame(){
  
  Container con = this.getContentPane();
  con.add(createPanel());
  this.setSize(600,400);
  this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  this.setDefaultLookAndFeelDecorated(true);
  this.setLocationRelativeTo(null);
  this.setVisible(true);
  
 }
 
 public JPanel createPanel(){
  
  panel = new JPanel();
  area = new JTextArea();
  panel.add(area);
  panel.add(createButton("save"));
  panel.add(createButton("open"));
  return panel;
 }
 

 public JButton createButton( String name ){
  
  JButton button = new JButton(name);
  button.addActionListener(new FileActionListener(this) );
  return button;
 }
 
 public static void main(String[] args) {
  
  new FileChooserFrame();

 }
 
 class FileActionListener implements ActionListener {

  FileChooserFrame frame ;
  
  public FileActionListener( FileChooserFrame frame ){
   this.frame = frame;
  }
  
  public void actionPerformed(ActionEvent e) {
   
   String command = e.getActionCommand();
   if( command.equals("save") ){
    
    JFileChooser fileChooser = new JFileChooser();
    FileNameExtensionFilter filter = new FileNameExtensionFilter("gif & jpg images ","jpg","gif");
    fileChooser.setFileFilter(filter);
    int d = fileChooser.showSaveDialog(frame);
    if( d==fileChooser.APPROVE_OPTION ){
     File file = fileChooser.getSelectedFile();
     frame.getArea().append(file.getName());
    }
    
    
   }
   
  }
  
 }

 public JTextArea getArea() {
  return area;
 }

 public void setArea(JTextArea area) {
  this.area = area;
 }
}