java GUI编程及文件对话框的使用

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.JLabel; 
 
 
 
@SuppressWarnings("serial") 
public class Filechooser extends JFrame implements ActionListener{ 
 
	JButton open=null; 
	public static void main (String[] args){ 
		new Filechooser();//构造一个指向用户的默认目录Filechooser 
	} 
	public Filechooser(){ 
		open=new JButton("打开"); 
		this.add(open); 
		this.setBounds(100,100,100,100); 
		this.setVisible(true); 
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
		open.addActionListener(this); 
	} 
	public void actionPerformed(ActionEvent e){ 
		JFileChooser j=new JFileChooser(); 
		j.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);//设置Filechooser 
		j.showDialog(new JLabel(),"选择");// 弹出具有自己定义 approve button的自己定义文件选择器对话框 
		File file=j.getSelectedFile(); 
			if(file.isDirectory()){ 
				System.out.println("目录        "+file.getAbsolutePath()); 
				 
			}else if(file.isFile()){ 
				System.out.println("目录        "+file.getAbsolutePath()); 
			} 
			System.out.println(j.getSelectedFile().getName()); 
		 
	} 
}