设计一个模拟银行存款和取款的程序

好好思考思考，网上类似的程序应该很多，对你提升很大的

package computerworkthreechapter;
import java.util.*;
public class three_1 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        money bank=new money();
        Scanner reader=new Scanner(System.in);
        System.out.print("欢迎使用Appilcation系统，请按任意(除0)键进入!");
        int choice=reader.nextInt();
        while(choice!=0){
            System.out.println("请输入选项:");
            System.out.println("1.存款");
            System.out.println("2.取款");
            System.out.println("3.显示余额");
            int a=reader.nextInt();
        switch(a){
        case 1:
            System.out.print("请输入存款金额：");
            double currency=reader.nextDouble();
            bank.putmoney(currency);
            bank.getyu();
            bank.put();
            System.out.print("\n\n");
            break;
        case 2:
            System.out.print("请输入取款金额：");
            double get=reader.nextDouble();
            bank.getmoney(get);
            bank.getyu();
            try{
            if(bank.yu<0){
                System.out.println("当前余额为:"+bank.money3);
                System.out.println("余额不足，不能取款!");
                choice=0;
                throw new IllegalArgumentException("余额为负");
            }
            else{
                System.out.print("取款成功!");
                bank.getyu();
                bank.put();
            }
            }   
            catch(IllegalArgumentException e)
            {
                System.out.print("出现的异常是:"+e.toString());
            }
            break;
        case 3:
            bank.getyu();
            System.out.println("当前余额为:"+bank.yu);
            System.out.print("\n\n");
            break;
        default:
            System.out.println("输入有误，请重新输入:");
        }
        }
    }

}
class money
{
    public static double yu;
    public static  double money1=0;
    public  static double money2=0;
    public  static double money3=0;
    public double bank1;
    Scanner reader=new Scanner(System.in);
    public void putmoney(double money)
    {
        this.money1+=money;
    }
    public void getmoney(double money)
    {
        this.money2+=money;
    }
    public void getyu()
    {
        yu=money1-money2;
    }
    public void put()
    {
        money3=yu;
    }
}