简易版ATM系统--java

第一次写这么多行代码，三百多行，虽然很简单，但是不容易啊，一个晚上，一边写一遍测试。

package com.test.hello.atm;

import java.util.ArrayList;
import java.util.Random;
import java.util.Scanner;

public class ATMSystem {

    public static void main(String[] args) throws InterruptedException {
        ArrayList<Account> accounts = new ArrayList<Account>();

        Scanner sc = new Scanner(System.in);
        while (true) {
            System.out.println("===============ATM系统=================");
            System.out.println("登录账户请输入：1");
            System.out.println("注册账户请输入：2");
            System.out.println("退出系统请输入：0");
            System.out.println("进入系统后台查看账户信息：777");

            int command = sc.nextInt();
            switch (command) {
                case 1:
                    login(accounts, sc);
                    break;
                case 2:
                    register(accounts, sc);
                    break;
                case 0:
                    return;
                case 777:
                    queryAll(accounts);
                    break;
                default:
                    System.out.println("没有这个操作，请重新输入");
                    break;
            }
        }
    }

    /**
     * 查询系统中所有账户的信息
     * @param accounts
     */
    private static void queryAll(ArrayList<Account> accounts) {
        System.out.println("===============后台查询=================");

        System.out.println("i卡号-----用户名------余额------限额");
        for (int i = 0; i < accounts.size(); i++) {
            Account acc = accounts.get(i);
            System.out.println(acc.getCarId() + "\t\t" +  acc.getUserName() + "\t\t" + acc.getMoney() + "\t\t" + acc.getQuoteMoney());
        }
    }

    /**
     * 个人界面，可以查询、存钱、转账、修改密码、注销此账户这些功能
     * @param accounts
     * @param sc
     * @throws InterruptedException
     */
    private static void login(ArrayList<Account> accounts, Scanner sc) throws InterruptedException {
        System.out.println("===============登录账户=================");
        if (accounts.size() == 0) {
            System.out.println("系统中没有账户，请先开户再来登录");
            return;
        }

        while (true) {
            System.out.println("请输入id卡号");
            String carId = sc.next();
            Account acc = getAccountByCarId(carId, accounts);
            if (acc != null) {
                System.out.println("请输入登录密码");
                String passwd = sc.next();
                if (acc.getPasswd().equals(passwd)) {
                    System.out.println("登录成功！");
                    System.out.println("===========这是" + acc.getUserName() + "的主场===========");
                    showUserCommand(acc, sc, accounts);
                    System.out.println("退出成功！即将回到主界面");
                    Thread.sleep(2000);
                    break;
                } else {
                    System.out.println("密码错误");
                }
            } else {
                System.out.println("系统中没有此id卡，请重新输入。。。");
            }
        }
    }

    /**
     * 个人操作界面
     * @param acc
     * @param sc
     * @param accounts
     */
    private static void showUserCommand(Account acc, Scanner sc, ArrayList<Account> accounts) {
        while (true) {
            System.out.println("请输入你需要的操作");
            System.out.println("查询请输入：0");
            System.out.println("存款请输入：1");
            System.out.println("取款请输入：2");
            System.out.println("转账请输入：3");
            System.out.println("改密码请输入：4");
            System.out.println("注销请输入：5");
            System.out.println("退出请输入：6");

            int command = sc.nextInt();
            switch (command) {
                case 0:
                    query(acc);
                    break;
                case 1:
                    depositMoney(acc, sc);
                    break;
                case 2:
                    drawMoney(acc, sc);
                    break;
                case 3:
                    trainforMoney(sc, acc, accounts);
                    break;
                case 4:
                    updatePasswd(acc,sc);
                    return;  //修改密码成功后，结束此方法，回到主界面
                case 5:
                    cancellation(acc, sc,accounts);  //注销账户
                    return;
                case 6:
                    return;
            }
        }
    }

    /**
     * 注销账户
     * @param acc
     * @param sc
     * @param accounts
     */
    private static void cancellation(Account acc, Scanner sc, ArrayList<Account> accounts) {
        System.out.println("你真的要注销此账户？？？  y/n");
        String flag = sc.next();
        if ("y".equals(flag)) {
            accounts.remove(acc);
            System.out.println("注销完成");
        } else if ("n".equals(flag)) {
            System.out.println("已经取消注销操作");
        }
    }

    /**
     * 修改账户的密码
     * @param acc
     * @param sc
     */
    private static void updatePasswd(Account acc, Scanner sc) {
        System.out.println("=================改密码界面==============：");
        while (true) {
            System.out.println("请输入新密码");
            String newPasswd = sc.next();
            System.out.println("请再一次输入新密码");
            String againNewPasswd = sc.next();
            if (newPasswd.equals(againNewPasswd)){
                if (newPasswd.equals(acc.getPasswd())) {
                    System.out.println("新密码不能与旧密码一致");
                } else {
                    acc.setPasswd(newPasswd);
                    System.out.println("修改密码成功");
                    return;
                }
            } else {
                System.out.println("两次输入的密码不一致，重新输");
            }
        }
    }


    /**
     * 转账功能
     * @param sc
     * @param acc
     * @param accounts
     */
    private static void trainforMoney(Scanner sc, Account acc, ArrayList<Account> accounts) {
        System.out.println("=================转账界面==============：");
        //判断系统中账户是否有2个或者更多
        if (accounts.size() < 2) {
            System.out.println("用户少于2个，不能实现转账，先开户吧");
            return;
        }
        //账户满足条件，判断此用户是否有钱
        if (acc.getMoney() == 0) {
            System.out.println("没钱，怎么转账");
            return;
        }
        while (true) {
            //满足以上条件，开始转账
            System.out.println("输入要转账的id卡号");
            String carId = sc.next();
            //不能给自己转账
            if (acc.getCarId().equals(carId)) {
                System.out.println("不能给自己转账");
                continue;
            }
            //首先判断输入的这个卡号是否存在
            Account account = getAccountByCarId(carId, accounts);
            if (account == null) {
                System.out.println("没有这个卡号，请重新输入");
            } else {
                String name = account.getUserName();
                System.out.println("有这个卡号");
                System.out.println("输入对方的用户名的姓氏" + "*" + name.substring(1));
                String inputName = sc.next();
                if (name.startsWith(inputName)) {
                    System.out.println("要转多少钱");
                    double money = sc.nextDouble();
                    if (money > acc.getQuoteMoney()) {
                        System.out.println("单词转账不能超过" + acc.getQuoteMoney());
                    } else {
                        acc.setMoney(acc.getMoney() - money);
                        account.setMoney(account.getMoney() + money);
                        System.out.println("转账成功");
                        break;
                    }
                } else {
                    System.out.println("你可能转错人了");
                }
            }
        }
    }

    /**
     * 取钱
     *
     * @param acc
     * @param sc
     */
    private static void drawMoney(Account acc, Scanner sc) {
        System.out.println("=================取钱界面==============：");
        if (acc.getMoney() > 0) {
            System.out.println("说吧取多少");
            double money = sc.nextDouble();
            if (money > acc.getQuoteMoney()) {
                System.out.println("每次最多取" + acc.getQuoteMoney());
            } else {
                if (acc.getMoney() > money) {
                    acc.setMoney(acc.getMoney() - money);
                    System.out.println("取钱成功，取了" + money);
                    query(acc);
                } else {
                    System.out.println("都没有这么多钱，还去取这么多钱，先进厂螺丝赚钱吧靓仔");
                }
            }
        } else {
            System.out.println("钱都没有，还取钱？？？！！");
            return;
        }
    }

    /**
     * 存钱
     * @param acc
     * @param sc
     */
    private static void depositMoney(Account acc, Scanner sc) {
        System.out.println("=================存钱界面==============：");
        System.out.println("存多少钱");
        double money = sc.nextDouble();
        acc.setMoney(acc.getMoney() + money);
        System.out.println("存钱成功");
        query(acc);

    }

    /**
     * 查询账户信息
     * @param acc
     */
    private static void query(Account acc) {
        System.out.println("=================查询界面==============：");
        System.out.println("卡号：" + acc.getCarId());
        System.out.println("用户名：" + acc.getUserName());
        System.out.println("余额：" + acc.getMoney());
        System.out.println("限额：" + acc.getQuoteMoney());

    }

    /**
     * 注册账户
     * @param accounts
     * @param sc
     * @throws InterruptedException
     */
    private static void register(ArrayList<Account> accounts, Scanner sc) throws InterruptedException {
        System.out.println("===============注册账户=================");
        Account account = new Account();
        System.out.println("请输入账户的name");
        String userName = sc.next();
        account.setUserName(userName);
        while (true) {
            System.out.println("请输入账户密码");
            String passwd = sc.next();
            System.out.println("再一次输入您的密码");
            String againPasswd = sc.next();
            if (passwd.equals(againPasswd)) {
                account.setPasswd(passwd);
                break;
            } else {
                System.out.println("您两次输入的密码不一样，请重新输入");
            }
        }
        System.out.println("请设置你的取款额度");
        double quoteMoney = sc.nextDouble();
        account.setQuoteMoney(quoteMoney);

        System.out.println("正在生成你的id卡号，请稍等。。。");
        Thread.sleep(2000);

        String carId = getRandomCarID(accounts);
        account.setCarId(carId);
        accounts.add(account);
        System.out.println("开户成功了" + account.getUserName());
        System.out.println("你的卡号为：" + account.getCarId());

    }

    /**
     * 随机生成一个6位数的数字组成的数字，并判断是否与系统中已有的id一样，一样则重新生成
     *
     * @param accounts
     * @return
     */
    private static String getRandomCarID(ArrayList<Account> accounts) {
        //随机生成6个数字
        while (true) {
            String carId = "";
            Random random = new Random();
            for (int i = 0; i < 6; i++) {
                carId += random.nextInt(10);
            }

            //判断是否与已有id一样
            Account account = getAccountByCarId(carId, accounts);
            if (account == null) {
                return carId;
            }
        }
    }

    /**
     * 根据id返回账户
     *
     * @param carId
     * @param accounts
     * @return
     */
    private static Account getAccountByCarId(String carId, ArrayList<Account> accounts) {
        for (int i = 0; i < accounts.size(); i++) {
            if (carId.equals(accounts.get(i).getCarId())) {
                return accounts.get(i);
            }
        }
        return null;
    }
}