代码的注释已经十分详尽，就不多说什么了。一切如下：
package arycra_07;
/*
账户类
*/
public class Account {
private String cardID; //卡号
private String userName; //户主
private String passWord; //密码
private double money; //余额
private double quotaMoney; //单次取款or转账限额
public Account() {
}
public Account(String cardID, String userName, String passWord, double quotaMoney) {
this.cardID = cardID;
this.userName = userName;
this.passWord = passWord;
this.quotaMoney = quotaMoney;
}
public String getCardID() {
return cardID;
}
public void setCardID(String cardID) {
this.cardID = cardID;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getPassWord() {
return passWord;
}
public void setPassWord(String passWord) {
this.passWord = passWord;
}
public double getMoney() {
return money;
}
public void setMoney(double money) {
this.money = money;
}
public double getQuotaMoney() {
return quotaMoney;
}
public void setQuotaMoney(double quotaMoney) {
this.quotaMoney = quotaMoney;
}
}
package arycra_07;
import java.util.ArrayList;
import java.util.Random;
import java.util.Scanner;
public class ATMSystem {
public static void main(String[] args) {
//准备系统需要的容器对象，用来存储账户对象
ArrayList<Account> accounts = new ArrayList<>();
//准备系统的首页，登录，开户
showMain(accounts);
}
/**
* 展示首页内容
*
* @param accounts 传入账户集合
*/
public static void showMain(ArrayList<Account> accounts) {
Scanner sc = new Scanner(System.in);
showMain_loop:
while (true) {
System.out.println("======================Welcome to my ATM system======================");
System.out.println("0. Exit the system");
System.out.println("1. Log in to your account");
System.out.println("2. Open an account");
System.out.println("Please input the number of your order: ");
String order = sc.next();
switch (order) {
case "0":
//退出
System.out.println("Exit successfully. Welcome back again!");
break showMain_loop;
case "1":
//登录
login(accounts, sc);
break;
case "2":
//开户
register(accounts, sc);
break;
default:
System.out.println("Illegal order. Try again.");
}
}
}
/**
* 完成用户登录操作
*
* @param accounts 传入账户集合
* @param sc 传入扫描器进行键盘输入
*/
private static void login(ArrayList<Account> accounts, Scanner sc) {
//考虑极端情况，用户在不存在账户的情况下强行登录
if (accounts.size() == 0) {
//没有任何账户，需要直接返回
System.out.println("No account exists in the system now. Open an account first.");
return;
}
System.out.println("======================Log in your account here======================");
//让用户录入卡号，根据卡号查询账户对象
while (true) {
System.out.println("Please input your cardID: ");
String cardID = sc.next();
//根据卡号查询账户对象，我们抽象成方法getAccountByCardID
Account acc = getAccountByCardID(cardID, accounts);
//判断账户对象是否存在，存在则说明没问题
if (acc != null) {
while (true) {
//账户对象存在，继续输入密码
System.out.println("Please input your password: ");
String password = sc.next();
//判断密码是否正确
if (acc.getPassWord().equals(password)) {
//密码正确，登录成功
//欢迎界面
System.out.println("Hello " + acc.getUserName() +
", now you have successfully entered the User Interface!");
System.out.println("Your cardID is " + acc.getCardID() + ".");
//展示系统登录后的操作界面
showUserOrder(sc, acc, accounts);
return; //结束登录方法
} else {
System.out.println("Wrong password. Try again.");
}
}
} else {
//账户对象不存在，继续循环
System.out.println("This account do not exist. Try again.");
}
}
}
/**
* 登录后展示用户操作界面
*
* @param sc 传入扫描器读取用户输入
* @param acc 传入用户登录的账户对象
* @param accounts 传入账户集合
*/
private static void showUserOrder(Scanner sc, Account acc, ArrayList<Account> accounts) {
while (true) {
System.out.println("======================User Interface======================");
System.out.println("1 Query account");
System.out.println("2 Deposit money");
System.out.println("3 Withdraw money");
System.out.println("4 Transfer accounts");
System.out.println("5 Change password");
System.out.println("6 Log out");
System.out.println("7 Delete your account");
System.out.println("Please input the number of your order:");
String order = sc.next();
switch (order) {
case "1" ->
//查询账户
queryAccount(acc);
case "2" ->
//存款
depositMoney(acc, sc);
case "3" ->
//取款
withdrawMoney(acc, sc);
case "4" ->
//转账
transferMoney(accounts, acc, sc);
case "5" ->
//修改密码
changePassword(acc, sc);
case "6" -> {
//登出
System.out.println("Log out successfully. Welcome back again!");
return; //结束当前方法返回
}
case "7" -> {
//注销
//删除当前账户即可
accounts.remove(acc);
System.out.println("Delete your account successfully.");
return; //结束当前方法返回
}
default -> System.out.println("Illegal order. Try again.");
}
}
}
private static void changePassword(Account acc, Scanner sc) {
System.out.println("======================Change Password======================");
while (true) {
System.out.println("Please input your previous password: ");
//要求用户输入正在使用的密码
String prePassword = sc.next();
//判断密码是否正确
if (acc.getPassWord().equals(prePassword)) {
System.out.println("Please input your new password: ");
String newPassword = sc.next();
System.out.println("Please confirm your new password: ");
//请用户确认自己的新密码
String okNewPassword = sc.next();
if (newPassword.equals(okNewPassword)) {
//确认无误，修改密码
acc.setPassWord(newPassword);
System.out.println("Change your password successfully!");
return; //返回
} else {
System.out.println("The passwords you input twice are inconsistent. Try again.");
}
} else {
System.out.println("Wrong password. Try again.");
}
}
}
/**
* 转账功能
*
* @param accounts 传入账户集合
* @param acc 传入当前登录的账户对象
* @param sc 传入扫描器进行键盘输入
*/
private static void transferMoney(ArrayList<Account> accounts, Account acc, Scanner sc) {
//判断系统中是否存在两个及以上账户，以支持转账操作
if (accounts.size() < 2) {
System.out.println("Sorry, there are no other accounts in the system " +
"for you to transfer money!");
return;
}
//如果当前账户余额为零
if (acc.getMoney() == 0) {
System.out.println("Your account is out of money now!");
return;
}
//说明系统中有至少两个账户且当前账户余额不为零，开启转账操作
while (true) {
System.out.println("Please input the cardID you want to transfer: ");
String cardID = sc.next();
Account account = getAccountByCardID(cardID, accounts); //查询输入的卡号是否存在
if (account != null) {
//卡号存在，判断是否在给自己转账
if (account.getCardID().equals(acc.getCardID())) {
//在给自己转账
System.out.println("Do not transfer money to yourself!");
} else {
//确认对方名字的第一个字符
String name = "*" + account.getUserName().substring(1);
System.out.println("Please complete the first character of " +
"his or her name: " + name);
String firstCharacter = sc.next();
//判断
if (account.getUserName().startsWith(firstCharacter)) {
//验证成功，开始转账
System.out.println("Please input the amount you want to transfer: ");
double amountMoney = sc.nextDouble();
//判断转账金额是否超过当前登录账户的余额或转账限额
if (amountMoney > acc.getQuotaMoney()) {
System.out.println("Exceed your transfer quota. Your quota is "
+ acc.getQuotaMoney() + " dollars. Try again.");
} else if (amountMoney > acc.getMoney()) {
//超过余额
System.out.println("Exceed your balance. Your balance is "
+ acc.getMoney() + " dollars now. Try again.");
} else {
//可以转账
acc.setMoney(acc.getMoney() - amountMoney);
account.setMoney(account.getMoney() + amountMoney);
System.out.println("Successfully transfer! You have transferred "
+ amountMoney + " to" + account.getUserName() + ".");
queryAccount(acc); //查看自己当前账户信息
return;
}
} else {
System.out.println("You get it wrong. Try again.");
}
}
} else {
//卡号不存在
System.out.println("The cardID you input do not exist. Try again.");
}
}
}
/**
* 取款
*
* @param acc 传入当前登录的账户对象
* @param sc 传入扫描器进行键盘输入
*/
private static void withdrawMoney(Account acc, Scanner sc) {
System.out.println("======================Withdraw Money======================");
//判断账户上还有没有钱
if (acc.getMoney() > 0) {
while (true) {
System.out.println("Please input your withdrawal amount");
double withdrawlAmount = sc.nextDouble();
//判断取款金额有没有超过单次取款限额
if (withdrawlAmount >= acc.getQuotaMoney()) {
System.out.println("Exceed your withdrawal quota. Try again. Your quota is "
+ acc.getQuotaMoney());
} else {
//判断取款金额有没有超过账户余额
if (withdrawlAmount >= acc.getMoney()) {
System.out.println("Exceed your balance. Your balance is "
+ acc.getMoney() + " dollars now. Try again.");
} else {
//可以取钱
acc.setMoney(acc.getMoney() - withdrawlAmount);
System.out.println("Successful withdrawal! You took out " + withdrawlAmount
+ " dollars. Now your account balance is " + acc.getMoney() + " dollars.");
return; //取钱成功后返回
}
}
}
} else {
System.out.println("Your account is out of money now!");
}
}
/**
* 存款功能
*
* @param acc 传入当前登录的账户对象
* @param sc 传入扫描器进行键盘输入
*/
private static void depositMoney(Account acc, Scanner sc) {
System.out.println("======================Deposit Money======================");
System.out.println("Please input your deposit amount: ");
double depositMoney = sc.nextDouble();
//直接把金额修改到账户对象的money属性中去
acc.setMoney(acc.getMoney() + depositMoney);
System.out.println("Deposit successfully!");
queryAccount(acc);
}
/**
* 查询当前登录的账户信息
*
* @param acc 传入当前登录的账户对象
*/
private static void queryAccount(Account acc) {
System.out.println("======================Account Details======================");
System.out.println("Your cardID is " + acc.getCardID());
System.out.println("Your name is " + acc.getUserName());
System.out.println("Your account balance is " + acc.getMoney() + " dollars");
System.out.println("Your current quota is " + acc.getQuotaMoney() + " dollars");
}
/**
* 开户功能
*
* @param accounts 传入账户集合
* @param sc 传入扫描器进行键盘输入
*/
private static void register(ArrayList<Account> accounts, Scanner sc) {
System.out.println("======================Open an account here======================");
//键盘录入 姓名 密码 确认密码
System.out.println("Please input your name: ");
String name = sc.next();
String password;
String okPassword;
while (true) {
System.out.println("Please input your password: ");
password = sc.next();
System.out.println("Please confirm your password: ");
okPassword = sc.next();
//判断两次输入的密码是否一致
if (okPassword.equals(password)) {
break;
} else {
System.out.println("Unsuccessfully confirm your password. Try again.");
}
}
System.out.println("Please input your quota of withdrawal and transfer: ");
double quotaMoney = sc.nextDouble();
//随机生成账户卡号并检查是否与其他账号重复，我们抽象出方法createCardID
String newCardID = createCardID(accounts);
//创建一个账户对象封装对象信息
Account account = new Account(newCardID, name, password, quotaMoney);
accounts.add(account);
System.out.println("Successfully open an account! Your cardID is " + account.getCardID() + ".");
}
/**
* 随机生成卡号并查重
*
* @param accounts 传入账户集合
* @return 返回一个8位新卡号
*/
public static String createCardID(ArrayList<Account> accounts) {
while (true) {
//生成一个8位新卡号
String newCardID = "";
Random r = new Random();
for (int i = 0; i < 8; i++) {
newCardID += r.nextInt(10);
}
//查重，检查新卡号是否重复
//根据卡号查询账户对象，我们抽象出方法getAccountByCardID
Account acc = getAccountByCardID(newCardID, accounts);
//判断账户对象是否存在，为null说明没问题
if (acc == null) {
//当前卡号未重复，可以开户
return newCardID;
}
}
}
/**
* 在账户集合中检索，判定卡号是否已经存在
*
* @param cardID createCardID方法中新生成的卡号
* @param accounts 账户集合
* @return 若重复则返回重复的账户对象，否则返回null
*/
public static Account getAccountByCardID(String cardID, ArrayList<Account> accounts) {
//根据卡号查询账户对象，查不到说明这个卡号未重复
for (Account acc : accounts) {
if (acc.getCardID().equals(cardID)) {
return acc;
}
}
return null; //查无此账户，卡号无重复
}
}
