简单的银行小案例

银行案例

• 实现银行功能

  • 用户输入正确卡号和密码可执行一下操作
  • 菜单如下：1.存款 2.取款 3.转账 4.查询余额 5.修改密码 0.退出

• 分析：

  • User类（cardNo、identity、username、password、phone、balance）
  • Bank类主要包括以下功能
    • 初始化用户（initial）
    • 用户登录（login）
    • 显示菜单
    • 存款（save）、取款（withDraw）、转账（trans）、查询余额（query）、修改密码（modifyPassword）
      该案例未实现保存数据的功能，再次运行仍为初始数据

package com.lemon.bank;
/**
 *用户类
 * @author gyq
 */

public class User {
    //卡号
    private String cardNo;
    //身份证号
    private String identity;
    //用户名
    private String username;
    //密码
    private String password;
    //电话
    private String phone;
    //余额
    private double balance;

    //默认构造方法
    public User() {
    }
    //带参构造方法


    public User(String cardNo, String identity, String username, String password, String phone, double balance) {
        this.cardNo = cardNo;
        this.identity = identity;
        this.username = username;
        this.password = password;
        this.phone = phone;
        this.balance = balance;
    }

    public String getCardNo() {
        return cardNo;
    }

    public void setCardNo(String cardNo) {
        this.cardNo = cardNo;
    }

    public String getIdentity() {
        return identity;
    }

    public void setIdentity(String identity) {
        this.identity = identity;
    }

    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 String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public double getBalance() {
        return balance;
    }

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

package com.lemon.bank;

import sun.security.util.Password;

import java.util.Scanner;

/**
 * 银行类
 * @author gyq
 */
public class Bank {
    //保存用户的数组
    private User[] users = new User[5];
    //保存个数
    private int size;
    //初始化方法
    public void initial(){
        //创建用户1
        User user1=new User();
        user1.setCardNo("1234567890");
        user1.setIdentity("411123456");
        user1.setUsername("xiaoming");
        user1.setPassword("123456");
        user1.setPhone("110");
        user1.setBalance (100000);
        //创建用户2
        User user2=new User("1234567891","411123451","xiaoli","123123","111",12000);
        //放入数组
        users[0]=user1;
        users[1]=user2;
        size=2;
        //System.out.println ("用户初始化完成！");
    }
    public Bank(){
        initial ();
    }
    //2用户登录
    public void login(){
        Scanner input = new Scanner (System.in);
        System.out.println ("请输入卡号：");
        String cardNo=input.next ();
        System.out.println ("请输入密码：");
        String password=input.next ();
        //遍历数组
        User u=null;
        for (int i = 0; i < size; i++) {
            if(users[i].getCardNo ().equals (cardNo)&&users[i].getPassword ().equals (password)){
                u=users[i];
                break;
            }
        }
        if (u!=null){
            //登陆成功！
            System.out.println ("登录成功！");
            //显示菜单
            showMenu(u);
        }else{
            System.out.println ("卡号或密码错误~！");
        }
    }
    //显示菜单
    public void showMenu(User u){
        Scanner input = new Scanner (System.in);
        System.out.println ("==============欢迎进入xxx银行系统=====当前用户："+u.getCardNo ()+"=================");

        do{
            System.out.println ("1.存款   2.取款    3.转账    4.查询余额  5.修改密码  0.退出");

            int choice=input.nextInt ();
            switch (choice){
                case 1://存钱
                    this.save (u);
                    break;
                case 2://取款
                    this.withDraw (u);
                    break;
                case 3://转账
                    this.trans (u);
                    break;
                case 4://查询余额
                    this.query (u);
                    break;
                case 5://修改密码
                    this.modifyPassword (u);
                    break;
                case 0://退出

                    return;
                default:
                    break;
            }
        }while (true);

    }
    //存钱
    public void save(User u){
        Scanner input = new Scanner (System.in);
        System.out.println ("请输入存款金额");
        double m = input.nextDouble ();
        if (m>0){
            u.setBalance (u.getBalance ()+m);
            System.out.println ("存钱成功：余额："+u.getBalance ());
        }else{
            System.out.println ("存钱失败，请重新输入！");
        }

    }
    //5.取钱
    public void withDraw(User u){
        Scanner input = new Scanner (System.in);
        System.out.println ("请输入取款金额");
        double m = input.nextDouble ();
        if (m>0){
            if (u.getBalance ()>=m) {
                u.setBalance (u.getBalance () - m);
                System.out.println ("取钱成功：余额：" + u.getBalance ());
            }else {
                System.out.println ("余额不足！");
            }
        }else{
            System.out.println ("取钱失败，请重新输入！");
        }

    }
    //6.转账
    public void trans(User u){
        Scanner input = new Scanner (System.in);
        System.out.println ("请输入对方卡号：");
        String cardNo = input.next ();
        System.out.println ("请输入转账金额：");
        double m=input.nextDouble ();
        //判断对方卡号是否存在
        User toUser=null;
        for (int i=0;i<size;i++){
            if (users[i].getCardNo ().equals (cardNo)){
                toUser=users[i];
                break;
            }
        }
        if (toUser!=null){//存在对方卡号
            if(u.getBalance ()>=m){
                //转账
                //扣钱
                u.setBalance (u.getBalance ()-m);
                //加钱
                toUser.setBalance (toUser.getBalance ()+m);
                System.out.println ("转账成功！当前您的余额为"+u.getBalance ());
            }else{
                System.out.println ("转账失败！余额不足！");
            }

        }else{
            System.out.println ("对方卡号不存在，请重新输入");
        }
    }
    //7查询余额
    public void query(User u){
        System.out.println ("卡号："+u.getCardNo ()+"用户名："+u.getUsername ()+"余额："+u.getBalance ());
    }
    //8修改密码
    public void modifyPassword(User u){
        Scanner input = new Scanner (System.in);
        System.out.println ("请输入新密码(密码长度6位)：");
        String newpassword=input.next ();
        if (newpassword.length ()==6){
            u.setPassword (newpassword);
            System.out.println ("修改成功！");
        }else {
            System.out.println ("输入密码不符合要求！");
        }
    }
}

package com.lemon.bank;

public class TestBank {
    public static void main(String[] args) {
        Bank bank = new Bank ();
        //bank.initial ();
        bank.login ();
    }
}