GUI编程及文件对话框的使用

package com.liang;import java.awt.event.ActionEvent;import java.io.File;import javax.swing.JButton;import javax.swing.JFileChooser;import javax.swing.JFrame;import javax.swing.JLabe;import javax.swing.JLabel;public class FileChooser extends JFrame implements Actionlistener{   /** *  */private static final long serialVersionUID = -8019177089931313613L;JButton open=null;   public static void main(String[] args){   new FileChooser();   }   public FileChooser(){   open=new JButton("open");   this.add(open);   this.setBounds(400, 200, 100, 100);   this.setVisible(true);   this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);   open.addActionListener((java.awt.event.ActionListener) this);   }   public void actionPerformed(ActionEvent e){   JFileChooser jfc=new JFileChooser();   jfc.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);   jfc.showDialog(new JLabel(),"选择");   File file=jfc.getSelectedFile();   if(file.isDirectory()){   System.out.println("文件夹:"+file.getAbsolutePath());   }else if(file.isFile()){   System.out.println("文件:"+file.getAbsolutePath());   }   System.out.println(jfc.getSelectedFile().getName());   }      }