JAVA2核心技术第七版上的ImageViewer运行不能照常显示

[独一无二的小马哥]

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

public class ImageViewer {
public static void main(String[] args){
JFrame frame=new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
class ImageViewerFrame extends JFrame{
private JLabel label;
private JFileChooser chooser;
private static final int DEFAULT_WIDTH=300;
private static final int DEFAULT_HEIGHT=400;
public ImageViewerFrame() {
setTitle("ImageViewer");
setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
label=new JLabel();
add(label);
chooser=new JFileChooser();
chooser.setCurrentDirectory(new File("."));
JMenuBar menuBar=new JMenuBar();
setJMenuBar(menuBar);
JMenu menu=new JMenu("File");
menuBar.add(menu);
JMenuItem openItem=new JMenuItem("Open");
menu.add(openItem);
openItem.addActionListener(new
ActionListener() {
public void actionPerformed(ActionEvent event) {
int result=chooser.showOpenDialog(null);
if(result==JFileChooser.APPROVE_OPTION){
String name=chooser.getSelectedFile

().getPath();
label.setIcon(new ImageIcon(name));
}
}
});
JMenuItem exitItem=new JMenuItem("Exit");
menu.add(exitItem);
exitItem.addActionListener(new
ActionListener() {
public void actionPerformed(ActionEvent event) {
System.exit(0);
}
});

}
}