运行程序无反应？不知有关问题出在那了？帮忙看一上

package cn.ts.jfilechooser;import java.awt.BorderLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.WindowAdapter;import java.awt.event.WindowEvent;import java.io.File;import java.io.FileInputStream;import java.util.Scanner;import javax.swing.JButton;import javax.swing.JFileChooser;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JPanel;import javax.swing.JScrollPane;import javax.swing.JTextArea;public class Demo {    public static void main(String args[]){            new Note();    }}class Note implements ActionListener {   private JTextArea area=new JTextArea(8,10);   private JFrame frame=new JFrame("文件选择");     private JButton open=new JButton("打开文件");   private JButton save=new JButton("存储文件");   private JLabel lab=new JLabel("现在没有打开文件");   private JPanel pan=new JPanel();   public void Note(){       this.pan.add(open);       this.pan.add(save);       frame.setLayout(new BorderLayout(3,3));       frame.add(this.lab);       frame.add(this.pan);       frame.add(new JScrollPane(this.area),BorderLayout.CENTER);       this.frame.setSize(330,180);       this.frame.setVisible(true);       this.frame.addWindowListener(new WindowAdapter(){           public void windowClosing(WindowEvent e){               System.exit(1);           }       });       this.open.addActionListener(this);       this.save.addActionListener(this);       frame.setSize(300,200);       frame.setVisible(true);          }    @Override    public void actionPerformed(ActionEvent arg0) {        // TODO Auto-generated method stub        File file=null;        int result=0;        JFileChooser fileChooser=new JFileChooser();        if(arg0.getSource()==this.open){            this.area.setText("");            fileChooser.setApproveButtonText("确定");            fileChooser.setDialogTitle("打开文件");            result=fileChooser.showOpenDialog(this.frame);            if(result==JFileChooser.APPROVE_OPTION){                file=fileChooser.getSelectedFile();                this.lab.setText("打开的文件名称"+file.getName());            }else if(result==JFileChooser.CANCEL_OPTION){                this.lab.setText("没有选择文件");            }else{                this.lab.setText("操作有误");            }            if(file!=null){                try{                    Scanner scan=new Scanner(new FileInputStream(file));                    scan.useDelimiter("\n");                    while(scan.hasNext()){                        this.area.append(scan.next());                        this.area.append("\n");                    }                    scan.close();                }catch(Exception e){                    this.lab.setText("读文件出错");                }            }        }           }}

 public static void main(String args[]){            new Note();    }