ATM機的主要操作如圖所示： 查詢餘額 存款 取款 改密 退卡

package study05;
import java.util.Scanner;
public class Demo05 {
	Scanner scan = new Scanner(System.in);
	int pass = 123456;
	int money = (int)(Math.random()*1000);
	int count = 0;//記錄輸入密碼的次數
	//登入
	public void login() {
		System.out.println("請輸入密碼：(只有3次機會)");
		int pass = scan.nextInt();
		//如果登入成功，進入主介面，否則繼續登入
		if(this.pass == pass) {
			mainUI();
		}else {
			if(count <2) {
				count++;
				System.out.println("密碼錯誤！請重新登陸！");
				login();
			}else {
				System.out.println("對不起！機會用完！請聯絡有關人員！");
			}
		}
		
	}
	
	
	//主介面
	public void mainUI() {
		System.out.println("請選擇您要進行的操作:");
		int type = scan.nextInt();
		switch (type) {
		case 1:
			deposit();
			break;
		case 2:
			withdrawMoney();
			break;
		case 3:
			search();
			break;
		case 4:
			changePass();
			break;
		case 5:
			takeCard();
			break;

		default:
			break;
		}
	}
	
	
	//存款
	public void deposit() {
		System.out.println("請輸入存款金額:");
		int money = scan.nextInt();
		if(money %100 != 0) {
			System.out.println("ATM只接收面值100元的人民幣");
			deposit();
		}else {
			System.out.println("存款成功！");
			this.money += money;
			mainUI();
		}
	}
	
	//取款
	public void withdrawMoney() {
		System.out.println("請輸入你要取款的金額:");
		int money = scan.nextInt();
		if(this.money < money) {
			System.out.println("對不起，餘額不足！");
			withdrawMoney();
		}else {
			if(money % 100 != 0 ) {
				System.out.println("請輸入整數金額");
				withdrawMoney();
			}else {
				System.out.println("取款成功！");
				this.money -= money;
				mainUI();
			}
		}
	}
	
	//查詢
	public void search() {
		System.out.println("你的餘額為:"+money);
		mainUI();
	}
		
	
	//改密
	public void changePass() {
		System.out.println("請輸入舊密碼:");
		int pass = scan.nextInt();
		if(this.pass == pass) {
			System.out.println("請輸入新密碼:");
			int newPass1 = scan.nextInt();
			System.out.println("請再次輸入密碼:");
			int newPass2 = scan.nextInt();
			if(newPass1 != newPass2) {
				System.out.println("兩次密碼不一致，請重新輸入：");
				changePass();
			}else {
				System.out.println("修改成功！");
				mainUI();
			}
		}else {
			System.out.println("密碼錯誤！請重新輸入：");
			changePass();
		}
	}
	
	//退卡
	public void takeCard() {
		System.out.println("謝謝使用!歡迎下次光臨！");
	}
	
	public static void main(String[] args) {
		new Demo05().login();
	}
}