JAVASE小练习 （今天做一个基于javase的银行ATM小练习）

实现的功能有
1，用户登录
2，用户开户（基于用户登录）
3，查询账户（基于用户登录）
4，存款
5，取款
6，转账
7，修改密码(只有三次确认密码的机会)
8，退出登录
9，注销

这个小例子可以让我们充分复习所学的javase知识

比如：

1，八种基本数据类型以及引用数据类型

2，set，get方法。

3，if语句的判断(对判断条件的掌握)

4，switch语句的熟练运用

6，for循环的使用

7，while分支语句的运用

8，break和continue的理解会更加深刻

9，list集合的使用

1，先建一个Account实体类来存入一下元素

private String cardID;//卡号
private String username;//姓名
private char gender;//性别
private String password;//密码
private double balance;//余额
private double quota;//每次提现额度

package com.itheima.yaoyao;

public class Account {
    private String cardID;//卡号
    private String username;//姓名
    private char gender;//性别
    private String password;//密码
    private double balance;//余额
    private double quota;//每次提现额度

    public Account(String cardID, String username, char gender, String password, double balance, double quota) {
        this.cardID = cardID;
        this.username = username;
        this.gender = gender;
        this.password = password;
        this.balance = balance;
        this.quota = quota;
    }

    public Account() {
    }

    public String getCardID() {
        return cardID;
    }

    public void setCardID(String cardID) {
        this.cardID = cardID;
    }

    public String getUsername() {
        return username+(gender == '男' ? "先生" : "女士");
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public char getGender(char gender) {
        return this.gender;
    }

    public void setGender(char gender) {
        this.gender = gender;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public double getBalance() {
        return balance;
    }

    public void setBalance(double balance) {
        this.balance = balance;
    }

    public double getQuota() {
        return quota;
    }

    public void setQuota(double quota) {
        this.quota = quota;
    }
}

2，再建一个ATM类来实现具体的业务逻辑

package com.itheima.yaoyao;

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

public class Atm {
     //定义一个ArrayList，用来存储所有的账户对象
     ArrayList<Account> list = new ArrayList<>();
     //准备一个键盘录入技术
     Scanner scanner = new Scanner(System.in);

     //定义一个变量，用来记录登录成功的账户
     private Account loginAccount;
     public void start(){
          while (true) {
               System.out.println("==欢迎进入ATM耀耀系统");
               System.out.println("1,用户登录");
               System.out.println("2,用户开户");
               System.out.println("请选择您想要的操作");
               int commend = scanner.nextInt();
               switch (commend){
                    case 1 :
                         //用户登录
                         login();
                         break;
                    case 2:
                         //用户开户
                          register();
                          break;
                    default:
                         System.out.println("对不起，选择的操作有误");
               }
          }

     }
          /*用户登录功能*/
          private void login() {
          System.out.println("==用户登录界面==");
          //1,判断集合中是否有帐户对象
          if (list.size() == 0) {
               System.out.println("先开户");
               register();
               return;
          }
          //说明系统中有对象
          while (true) {
               //2，让用户输入卡号
               System.out.println("请输入你的卡号");
               String carId = scanner.next();
               //3,判断卡号是否存在
               Account acc = getAccountByCarId(carId);
               //判断得到的帐户对象是否为null
               if (acc == null) {
                    System.out.println("您输入的卡号不正确请重新输入");
                    continue;
               }
               //说明卡号正确了
               //4，让用户输入密码
               while (true) {
                    System.out.println("请输入您的密码");
                    String password = scanner.next();
                    if (password.equals(acc.getPassword())){
                         //密码对了
                         //TDOO操作界面方法
                         loginAccount = acc;
                         showAllCommands();
                         return;
                    }else {
                         System.out.println("对不起您输入的密码有误，请重新输入");
                    }
               }
          }
     }

     /**
      * 用户登录成功后的操作页
      */
     private void showAllCommands() {
          while (true) {
               System.out.println("==用户操作界面==");
               System.out.println("欢迎"+loginAccount.getUsername());
               System.out.println("1,查询账户");
               System.out.println("2,存款");
               System.out.println("3,取款");
               System.out.println("4,转账");
               System.out.println("5,修改密码");
               System.out.println("6,退出");
               System.out.println("7,注销");
               System.out.println("请选择");
               int commend = scanner.nextInt();
               switch (commend){
                    case 1:
                         //查询账户
                         queryAccount();
                         break;
                    case 2:
                         //存款
                         deposit();
                         break;
                    case 3:
                         //取款
                         withdraw();
                         break;
                    case 4:
                         //转账
                         transfer();
                         break;
                    case 5:
                         //修改密码
                         boolean s = updatepasswprd();
                         if (s){
                              //修改成功
                              return;
                         }
                         break;
                    case 6:
                         //退出登录
                         System.out.println("退出成功，欢迎下次光临");
                         return;
                    case 7:
                         //注销账户
                        boolean f = deleteAccount();
                        if (f){
                             //销户成功
                             return;
                        }
                        //销户失败
                         break;
                    default:
                         System.out.println("您输入的命令不存在，重新输入");

               }
               continue;
          }

     }

     /**
      * 用户修改密码功能
      * @return
      */
     private boolean updatepasswprd() {
          System.out.println("==用户修改密码==");
          for (int i = 0; i < 3; i++) {

          System.out.println("请输入当前密码");
          String oldpassword = scanner.next();
          if (!oldpassword.equals(loginAccount.getPassword())) {
               System.out.println("您输入的密码错误您还有"+(2-i)+"次机会");

          }else {
               //旧密码输入正确·
               while (true){
                    System.out.println("请输入新密码");
                    String newpassword = scanner.next();
                    System.out.println("请再次输入新密码");
                    String renewpassword = scanner.next();
                    if (renewpassword.equals(newpassword)) {
                         loginAccount.setPassword(newpassword);
                         System.out.println("密码修改成功");
                         return true;
                    }else {
                         System.out.println("您两次输入的密码不一致，请重新输入");
                    }
               }
          }}
          return false;
     }

     /**
      * 用户销户功能
      * @return
      */
     private boolean deleteAccount() {
          while (true) {
               System.out.println("==用户销户页面==");
               //提醒用户是否要销户
               System.out.println("您确定要销户吗");
               String command = scanner.next();
               //判断用户输入的是什么
               switch (command) {
                    case "y":
                         //销户
                         //判断账户中是否还有钱
                         if (loginAccount.getBalance() != 0) {
                              System.out.println("您的账户还有钱");
                              return false;
                         } else {
                              //销户
                              list.remove(loginAccount);
                              System.out.println("销户成功");
                              return true;
                         }
                    case "n":
                         //不销户
                         System.out.println("账户保留");
                         return false;
                    default:
                         System.out.println("输入有误：y/n");
               }
          }

     }

     /**
      * 用户转账功能
      */
     private void transfer() {
          System.out.println("==用户转账==");
          //1，判断系统中是否有二个或二个以上账户
          if (list.size()==1) {
               System.out.println("当前系统账户不足");
               return;
          }
          //2，判断账户中是否有钱
          if (loginAccount.getBalance()==0) {
               System.out.println("账户一毛没有");
               return;
          }
          while (true) {
               //3，输入转账金额
               System.out.println("请输入转账金额");
               double money = scanner.nextDouble();
               //4,判断是否超过账户余额
               if (money > loginAccount.getBalance()) {
                    System.out.println("余额不足最多转"+loginAccount.getBalance()+"元");
                    continue;
               }
               //账户余额充足
               while (true) {
                    System.out.println("输入对方账户");
                    String targetCardId = scanner.next();
                    Account targetAccount = getAccountByCarId(targetCardId);
                    //先判断卡号是否存在
                    if (targetAccount == null) {
                         System.out.println("卡号不存在");
                         continue;
                    }
                    //判断不能给自己转账
                    if (targetAccount.getCardID().equals(loginAccount.getCardID())) {
                         System.out.println("您不能给自己转账");
                         continue;
                    }
                    //卡号没问题
                    //让用户验证对方的姓氏
                    String targetUsername = targetAccount.getUsername();
                    System.out.println("请输入*"+targetUsername.substring(1)+"的名字首字母");
                    String targetname = scanner.next();
                    if (targetname.equals(targetUsername.substring(0,1))) {
                         //姓氏通过，可以转账
                         loginAccount.setBalance(loginAccount.getBalance()-money);
                         targetAccount.setBalance(targetAccount.getBalance()+money);
                         System.out.println("转账成功，转账后您的余额为"+loginAccount.getBalance());
                         return;
                    }else {
                         System.out.println("姓氏验证没通过");
                    }
               }
          }
     }

     /**
      * 用户取款功能
      */

     private void withdraw() {
          System.out.println("==用户取款==");
          //1,判断用户余额是否大于100元
          if (loginAccount.getBalance() < 100) {
               System.out.println("你的余额不足");
               return;
          }
          //账户余额大于100
          //2，提示用户输入取款金额
          while (true) {
               System.out.println("==用户取款==");
               System.out.println("请输入取款金额");
               double money = scanner.nextDouble();

               //3,判断取款金额有无超过余额
               if (loginAccount.getQuota() < money) {
                    System.out.println("对不起您超过限额");
                    continue;
               }
              //4，说明取款金额没有超过限额
               //判断余额是否足够
               if (loginAccount.getBalance() < money) {
                    System.out.println("对不起余额不足 您的余额为"+loginAccount.getBalance());
                    continue;
               }
               //余额也够，可以取钱
               loginAccount.setBalance(loginAccount.getBalance()-money);
               System.out.println("取款"+money+"元成功你的余额为"+loginAccount.getBalance());
               break;
          }
     }

     /**
      * 用户存款功能
      */
     private void deposit() {
          System.out.println("请输入存款金额");
          double money = scanner.nextDouble();
          //把存的钱加入余额中
          loginAccount.setBalance(loginAccount.getBalance()+money);
          System.out.println("存款后您的余额是"+loginAccount.getBalance());

     }

     /**
      * 用户查询账户功能
      */
     private void queryAccount() {
          System.out.println("查询页面");
          System.out.println("您的姓名是"+loginAccount.getUsername());
          System.out.println("您的卡号是"+loginAccount.getCardID());
          System.out.println("您的余额是"+loginAccount.getBalance());
     }

     /*
     * 用户开户功能
     * */
     private  void register() {
          System.out.println("==用户开户界面==");
          //1，准备一个账户对象
          Account account = new Account();
          //让用户输入先关信息
          System.out.println("请输入您的姓名");
          String username = scanner.next();
          account.setUsername(username);

          while (true){
               System.out.println("请输入您的性别");
               char gender = scanner.next().charAt(0);
               if (gender == '男'||gender=='女') {
                    account.setGender(gender);
                    break;
               }else {
                    System.out.println("对不起您输入的性别有误");
               }
          }
          while (true){
               System.out.println("亲输入您的密码");
               String password = scanner.next();
               System.out.println("请再次输入您的密码");
               String repassword = scanner.next();
               if (password.equals(repassword)) {
                    account.setPassword(password);
                    break;
               }else {
                    System.out.println("对不起您输入的密码重复");
               }
          }
          System.out.println("亲输入您的提款限额");
          double quota = scanner.nextDouble();
          account.setQuota(quota);

          while (true){
               //生成卡号alexis
               String carId = createCarId();
               //判断生成的卡号是否重复
               Account account1 =getAccountByCarId(carId);
               if (account1 == null) {
                    //卡号不存在
                    account.setCardID(carId);
                    break;
               }
          }
          //3,把账户对象添加到集合当中，才算真正开户成功
          list.add(account);
          System.out.println("恭喜你，开户成功，您的卡号是："+account.getCardID());

     }

     /**
      *   根据卡号查找对象
      * @return carId
      * 找到的账户对象
      */
     private Account getAccountByCarId(String carId){
          //1，遍历账户集合，判断拿到的账户对象卡号是否是要查找到的
          for (int i = 0; i < list.size(); i++) {
               Account account = list.get(i);
               if (account.getCardID().equals(carId)) {
                    //找到了
                    return account;
               }
          }
          //找不到
          return null;
     }

     /**
      * 生成1个随机卡号
      * @return生成的随即卡号
      */
     private String createCarId(){
          //1,定义一个空字符串，用来存储卡号
          String carId = "";
          //2,生成八位随机卡号
          //先单独生成一位：1-9
          Random random = new Random();
          carId += random.nextInt(9)+1;
          //在生成7位1-9
          for (int i = 0; i < 7; i++) {
               carId+=random.nextInt(10);
          }
          //返回生成的随机卡号
          return carId;

     }
}

3，最后建一个测试来测试一下

package com.itheima.yaoyao;

public class Test {
    public static void main(String[] args) {
        Atm atm = new Atm();
        atm.start();
    }
}