做了一个简单的系统，首先jframe窗口 点击确定，输入用户名 11，密码 11，进入系统操作。输入4 退出时，跳出一jframe界面，可为什么显示不了？

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


 class KaiShi extends JFrame implements ActionListener{
     KaiShi(){
        Font f=new Font("楷体_GB2312",Font.BOLD,32);
        Color c2=new Color(255,0,0);
     JLabel label1=new JLabel("欢迎使用ATM模拟自动取款机程序,点击确定进入！");
     JButton button1=new JButton("确定");
   label1.setForeground(c2);
   label1.setFont(f);
   button1.setForeground(c2);
   button1.setFont(f);
     add(label1,BorderLayout.CENTER);
     add(button1,BorderLayout.SOUTH);
     setBounds(500,100,800,300);
   setVisible(true);
      validate();
     
    button1.addActionListener(this);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
    public void actionPerformed(ActionEvent e){
         dispose();
         ATM atm=new ATM();
      try{
           atm.Load_Sys();
           
          }catch(Exception ee){}
    }
}



 class TuiChu extends JFrame implements ActionListener{
     TuiChu(){
   
        Font f=new Font("楷体_GB2312",Font.BOLD,32);
        Color c2=new Color(255,0,0);
     JLabel label1=new JLabel("感谢您使用本系统，欢迎下次再来，再见！");
     JButton button1=new JButton("确定");
   label1.setForeground(c2);
   label1.setFont(f);
   button1.setForeground(c2);
   button1.setFont(f);
     add(label1,BorderLayout.CENTER);
     add(button1,BorderLayout.SOUTH);
     setBounds(100,100,800,300);
   setVisible(true);
     validate();
     
    button1.addActionListener(this);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
    public void actionPerformed(ActionEvent e){
         System.exit(1);
}
}




/*该类为实现客户信息及部分功能*/
class Account {
private String code =null; //信用卡号
private String name =null; //客户姓名
private String password=null; //客户密码
private double money =0.0; //卡里金额

/********************/
public Account(String code,String name,String password,double money)
{
   this.code=code;
   this.name=name;
   this.password=password;
   this.money=money;
}

protected String get_Code() {
   return code;
}

protected String get_Name() {
   return name;
}

protected String get_Password() {
   return password;
}

public double get_Money() {
   return money;
}

/*得到剩余的钱的数目*/
protected void set_Balance(double mon) {
   money -= mon;
}
}

/**********实现具体取款机功能*********/
class ATM {
Account act;

public ATM() {
   act=new Account("11","Devil","11",50000);
}

/**********登陆系统**********/
protected void Load_Sys() throws Exception
{
   String card,pwd;
   int counter=0;
   
   BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
   do {
System.out.println("请输入您的信用卡号:");
card=br.readLine();
System.out.println("请输入您的密码:");
pwd=br.readLine();

if(!isRight(card,pwd))
{
System.out.println("您的卡号或密码输入有误.");
counter++;
}
else
SysOpter();

   }while(counter<3);
   Lock_Sys();
}

/**********系统操作**********/
protected void SysOpter() throws Exception
{
   int num;
   BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
   System.out.println("\n请选择您要操作的项目(1-4):");
   System.out.print("\n 1.>取款."+"\n"+
   " 2.>查询信息."+"\n"+
   " 3.>密码设置."+"\n"+
   " 4.>退出系统."+"\n");
   num=br.read();   //num为ASICC码转换的整数
   switch(num) {
   case 49: BetBalance(); break;
   case 50: Inqu_Info(); break;
   case 51: Set_Password(); break;
   case 52: Exit_Sys();   break;
   }
  
}

/**********信息查询**********/
protected void Inqu_Info() throws Exception  {
  do{ System.out.print("---------------------\n"+
   act.get_Code()+"\n"+
   act.get_Name()+"\n"+
   act.get_Money()+"\n"+
   "-----------------------");
   SysOpter();
  }while(true);

}

/**********取款**********/
public void BetBalance() throws Exception
{
   String str=null,str1;
   BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
   do {
System.out.println("请输入您要取的数目:");
str=br.readLine();
str1=String.valueOf(act.get_Money());
if((str1)>0) {
System.out.println("超过已有的钱数,请重新输入您要取的数目:");
}
else {
/*操作成功*/
// act.set_Balance(str);
System.out.println("取款成功,请收好您的钱.");
SysOpter();
}
   }while(true);
   
}

/**********判断卡内是否有钱**********/
protected boolean isBalance() {
   if(act.get_Money()<0) {  
 System.out.println("对不起,您的钱数不够或卡已透支.");
  //return false;
   }
   return true;
}

/********卡号密码是否正确******/
protected boolean isRight(String card,String pwd)
{
   if(act.get_Code().equals(card) && act.get_Password().equals(pwd))
return true;
   else
return false;
}

/**********密码修改**********/
protected void Set_Password() throws Exception
{
   String pwd=null;
   int counter=0;
   BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
   do {
System.out.println("请输入旧密码:");
pwd=br.readLine();
if(act.get_Password().equals(pwd))
{
do {
    System.out.println("请输入新密码:");
    String pwd1=br.readLine();
    System.out.println("请再次输入新密码:");
    String pwd2=br.readLine();
    if(!pwd1.equals(pwd2))
    {
   System.out.println("两次输入不一致,请再次输入.");
    }
    else
    {
   System.out.println("密码修改成功,请使用新密码.");  
   SysOpter();
    }
}while(true);
}
   }while(counter>3);
   
}

/**********锁定机器**********/
protected void Lock_Sys() {
   System.out.println("对不起,您的操作有误,卡已被没收.");
   JFrame tui=new JFrame("没收窗口");
        Font f=new Font("楷体_GB2312",Font.BOLD,32);
        Color c2=new Color(255,0,0);
         JLabel label1=new JLabel("对不起,您的操作有误,卡已被没收！");
   label1.setForeground(c2);
   label1.setFont(f);
     tui.add(label1);
     tui.setBounds(500,100,700,300);
     tui.setVisible(true);
      tui.validate();
    tui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

/**********结束系统**********/
protected void Exit_Sys() {
        TuiChu tuichu=new TuiChu();
}
}

public class Text1
{
public static void main(String[] args)
{  
     KaiShi kaishi=new KaiShi();
   
}
}

恩，正常了。非常感谢！

恩，正常了。非常感谢！