1、实现类

package Meal;
import java.util.ArrayList;import java.util.Scanner;
public class t {
//点菜    Scanner s= new Scanner(System.in);    private int chose;    private double sum;    //private double price=0.0;    ArrayList<String> dish = new ArrayList<String>();    ArrayList<Double> price = new ArrayList<Double>();    public void begin(){
do{
System.out.println("0、退出");            System.out.println("1、菜单");            System.out.println("2、已点菜品");            System.out.println("3、买单");            System.out.print("请选择:");            chose=s.nextInt();            switch (chose){
case 1:
Show();                    System.out.println();                    break;                case 2:
dished();                    System.out.println();                    break;                case 3:
sum_();                    System.out.println();                    break;                case 0:
System.out.println("程序退出!");                    exit_();                    break;            }
}while(true);    }
//已点菜品    public void dished(){
System.out.println("\t\t\t\t\t《已点菜品》");        for (int i = 0; i <dish.size() ; i++) {
System.out.println((i+1)+"、"+dish.get(i));        }
}
//买单    public void sum_(){
System.out.println("请稍等，正在结账.....");        for (int i = 0; i <price.size() ; i++) {
sum+=price.get(i);        }
System.out.printf("您总共消费:%.1f元!",sum);        System.out.println();
    }
//菜单    public void Show(){
f_show();        System.out.println("1、鱼香肉丝  \t30.2");        System.out.println("2、干煸四季豆\t22.4");        System.out.println("3、泡椒牛肉 \t44.3");        System.out.println("4、水煮肉片 \t35.9");        System.out.println("5、拍黄瓜  \t13.2");        f_show();        do{
System.out.print("请选择菜品:");            chose = s.nextInt();            switch (chose){
case 1:
dish.add("鱼香肉丝");                    price.add(30.2);                    break;                case 2:
dish.add("干煸四季豆");                    price.add(22.4);                    break;                case 3:
dish.add("泡椒牛肉");                    price.add(44.3);                    break;                case 4:
dish.add("水煮肉片");                    price.add(35.9);                    break;                case 5:
dish.add("拍黄瓜");                    price.add(13.2);                    break;                case 0:
System.out.println("退出选菜!");                    break;                default:
System.out.println("选择有误");                    break;            };        }while(chose!=0);        }
public void f_show(){
for (int i = 0; i <50 ; i++) {
System.out.print("-");            if (i==25)
{
System.out.print("《菜单》");            }
}
System.out.println();    }
public void exit_(){
System.exit(0);    }
}

2、主类

package Meal;
public class m {
public static void main(String[] args) {
t tt = new t();        tt.begin();    }
}