Java写一个热水卡充值系统

package test;

import java.util.Scanner;

//定义test类
public class Test {
	//用于存储账户信息
	public String account;
	public double[] moneyData;
	
	public Test(String account) {
		this.account = account;
	}
	//定义菜单方法
	public void showMain() {
		System.out.printf("欢迎使用热水卡充值系统，当前账号：%s\n",account);
		System.out.println("【1】 热水卡充值");
		System.out.println("【2】 查询充值金额");
		System.out.println("【3】 支付充值金额");
		System.out.println("【0】 退出系统");
	}
	//热水卡充值方法
	public void saveOrder() {
		Scanner but = new Scanner(System.in);
		System.out.println("请输入充值的数量：");
		this.moneyData = new double[but.nextInt()];
		for(int i = 0; i < this.moneyData.length ; i ++) {
			System.out.printf("请输入第 %d 张热水卡的金额：",i+1);
			this.moneyData[i] = but.nextDouble();
		}
		//充值逻辑
	}
	//查询充值总金额的方法
	public double getOrder(double[] data) {
		//查询逻辑
		int money = 0;
		for(int i = 0; i < data.length ; i ++) {
			money += data[i];
		}
		return money;
	}
	//定义支付的方法
	public double payOrder(double[] data) {
		//支付逻辑
		Scanner but = new Scanner(System.in);
		int PayMoney = but.nextInt();
		int PayMoneyAdd = 0;
		for(int i = 0 ; i < this.moneyData.length ; i ++) {
			PayMoneyAdd += data[i];
		}
		return PayMoney - PayMoneyAdd;
	}
	
	public static void main(String[] args) {
		//创建一个键盘输入方法
		Scanner but = new Scanner(System.in);
		System.out.println("请输入账户:");
		//传入全局变量，存放账户信息 
		Test test = new Test(but.next());
		//初始化数组
		test.moneyData = new double[0];
		//实现充值方法
		while(true) {
			//展示菜单
			test.showMain();
			//提示输入选择
			System.out.println("请输入您的选择：");
			//定义变量存放输入选项
			String menu = but.next();
			switch(menu) {
				case "1"://充值
					test.saveOrder();
					break;
				case "2"://查询
					if(test.moneyData.length == 0) {
						System.out.println("未存在充值记录！");
					}else {
						double TextData = test.getOrder(test.moneyData);
						System.out.printf("当前存在%d张热水卡充值记录，您需支付充值金额为：%.2f\n",test.moneyData.length,TextData);
					}
					break;
				case "3"://支付
					System.out.println("请输入充值金额：");
					double MoneyData = test.payOrder(test.moneyData);
					do {
						System.out.println("您输入的金额小于充值金额，请重新输入");
						MoneyData = test.payOrder(test.moneyData);
					}while(MoneyData < 0);
					int PayMoneyAdd = 0;
					for(int i = 0 ; i < test.moneyData.length ; i ++) {
						PayMoneyAdd += test.moneyData[i];
					}
					System.out.printf("充值成功，共支付金额%.2f元，返回金额%.2f元\n",(double)PayMoneyAdd,MoneyData);
					test.moneyData = new double[0];
					break;
				case "0"://退出
					System.out.println("您已退出此系统");
					System.exit(0);
					break;
				default://其它
					System.out.println("无此选项,请重新选择");
					test.showMain();
					System.out.println("请输入您的选择：");
					break;
			}
		}

	}

}