java建立一个简单的图片浏览器

源代码：

package filterDialog1;

import java.awt.Dimension;
import java.awt.Image;
import java.awt.event.*;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.io.*;

import javax.swing.*;
import javax.swing.filechooser.*;
import javax.swing.filechooser.FileFilter;
public class ImageFrame{
public static void main(String args[]){
Image1Frame ia1=new Image1Frame();
ia1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
ia1.setVisible(true);
}
}
class Image1Frame extends JFrame{
public static final int DEFAULT_WIDTH=400;
public static final int DEFAULT_HEIGHT=300;
private JFileChooser chooser;
private JLabel label;
public Image1Frame(){
setSize(DEFAULT_WIDTH,DEFAULT_HEIGHT);
JMenuBar menuBar=new JMenuBar();
setJMenuBar(menuBar);
JMenu menu=new JMenu("File");
menuBar.add(menu);
JMenuItem openItem=new JMenuItem("Open");
openItem.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent event){
chooser.setCurrentDirectory(new File("."));
//show file chooser dialog
int result=chooser.showOpenDialog(Image1Frame.this);
}
});
menu.add(openItem);
JMenuItem exitItem=new JMenuItem("Exit");
exitItem.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent event){
System.exit(0);
}
});
menu.add(exitItem);
//User a label to diaplay the images
label=new JLabel();
add(label);
//set up file chooser
chooser=new JFileChooser();
//accept all image files ending with .jpg .jpeg .gif
FileNameExtensionFilter filter=new
FileNameExtensionFilter("images files","jpeg","gif","jpg");
chooser.setFileFilter(filter);

chooser.setAccessory(new ImagePreviewer(chooser));
// 设置 FileChooserUI 中的 ApproveButton 内使用的文本
chooser.setApproveButtonText("Open");
//窗口标题
chooser.setDialogTitle("DialogTitle");
chooser.setFileView(new FileIconView(filter,new
ImageIcon("palette.gif")));
}
}
class ImagePreviewer extends JLabel{
public ImagePreviewer(JFileChooser chooser){
setPreferredSize(new Dimension(200,200));
setBorder(BorderFactory.createEtchedBorder());

chooser.addPropertyChangeListener(new PropertyChangeListener()
{
@Override
public void propertyChange(PropertyChangeEvent evt) {

if(evt.getPropertyName()==JFileChooser.SELECTED_FILE_CHANGED_PROPERTY){
//the user has selected a new file
File f=(File)evt.getNewValue();
if(f==null){
setIcon(null);
return;
}
//read the image into an icon
ImageIcon icon=new ImageIcon(f.getPath());
//if the icon is too large to fit,scale
it
if(icon.getIconWidth()>getWidth()) icon=new
ImageIcon(icon.getImage().getScaledInstance(getWidth(), -1,
Image.SCALE_DEFAULT));
setIcon(icon);
}
}
});
}
}
class FileIconView extends FileView
{
private FileFilter
filter;
private Icon icon;

public
FileIconView(FileFilter aFilter, Icon anIcon)
{

filter = aFilter;
icon
= anIcon;
}

public Icon getIcon(File
f)
{
if
(!f.isDirectory() && filter.accept(f)) return icon;
else
return null;
}
}