Java订餐系统简易版代码

这里提供一个简单的Java订餐系统的代码示例，包含用户登录、菜品选择和订单管理等功能：

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

public class OrderSystem {
    // 菜品列表
    private static ArrayList<Dish> dishes = new ArrayList<>();
    // 购物车
    private static ArrayList<Dish> cart = new ArrayList<>();
    // 订单列表
    private static ArrayList<Order> orders = new ArrayList<>();

    public static void main(String[] args) {
        // 初始化菜品列表
        initDishes();

        // 用户登录
        User user = login();

        // 菜品选择
        selectDishes();

        // 订单管理
        manageOrders(user);
    }

    // 初始化菜品列表
    private static void initDishes() {
        dishes.add(new Dish("鱼香肉丝", 20));
        dishes.add(new Dish("宫保鸡丁", 18));
        dishes.add(new Dish("红烧肉", 25));
    }

    // 用户登录
    private static User login() {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入用户名：");
        String username = scanner.nextLine();
        System.out.println("请输入密码：");
        String password = scanner.nextLine();
        User user = new User(username, password);
        System.out.println("登录成功，欢迎您，" + username + "！");
        return user;
    }

    // 菜品选择
    private static void selectDishes() {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请选择菜品：");
        for (int i = 0; i < dishes.size(); i++) {
            Dish dish = dishes.get(i);
            System.out.println((i + 1) + ". " + dish.getName() + "（￥" + dish.getPrice() + "）");
        }
        while (true) {
            System.out.println("请输入菜品编号（输入0结束选择）：");
            int num = scanner.nextInt();
            if (num <= 0 || num > dishes.size()) {
                break;
            }
            Dish dish = dishes.get(num - 1);
            cart.add(dish);
            System.out.println(dish.getName() + "已加入购物车。");
        }
    }

    // 订单管理
    private static void manageOrders(User user) {
        Scanner scanner = new Scanner(System.in);
        while (true) {
            System.out.println("请选择操作：");
            System.out.println("1. 查看购物车");
            System.out.println("2. 修改购物车");
            System.out.println("3. 提交订单");
            System.out.println("4. 查看历史订单");
            System.out.println("5. 退出系统");
            int num = scanner.nextInt();
            switch (num) {
                case 1:
                    viewCart();
                    break;
                case 2:
                    modifyCart();
                    break;
                case 3:
                    submitOrder(user);
                    break;
                case 4:
                    viewOrders(user);
                    break;
                case 5:
                    System.out.println("欢迎下次光临！");
                    return;
                default:
                    System.out.println("输入有误，请重新输入。");
                    break;
            }
        }
    }

    // 查看购物车
    private static void viewCart() {
        System.out.println("购物车：");
        for (int i = 0; i < cart.size(); i++) {
            Dish dish = cart.get(i);
            System.out.println((i + 1) + ". " + dish.getName() + "（￥" + dish.getPrice() + "）");
        }
    }

    // 修改购物车
    private static void modifyCart() {
        Scanner scanner = new Scanner(System.in);
        viewCart();
        System.out.println("请输入要修改的菜品编号：");
        int num = scanner.nextInt();
        if (num <= 0 || num > cart.size()) {
            System.out.println("输入有误，请重新输入。");
            return;
        }
        System.out.println("请输入修改后的份数：");
        int count = scanner.nextInt();
        if (count <= 0) {
            System.out.println("输入有误，请重新输入。");
            return;
        }
        Dish dish = cart.get(num - 1);
        dish.setCount(count);
        System.out.println("购物车已修改。");
    }

    // 提交订单
    private static void submitOrder(User user) {
        if (cart.isEmpty()) {
            System.out.println("购物车为空，无法提交订单。");
            return;
        }
        double totalPrice = 0;
        for (Dish dish : cart) {
            totalPrice += dish.getPrice() * dish.getCount();
        }
        Order order = new Order(cart, totalPrice, user);
        orders.add(order);
        cart.clear();
        System.out.println("订单已提交，总价为￥" + totalPrice + "。");
    }

    // 查看历史订单
    private static void viewOrders(User user) {
        System.out.println("历史订单：");
        for (Order order : orders) {
            if (order.getUser().equals(user)) {
                System.out.println(order);
            }
        }
    }
}

class User {
    private String username;
    private String password;

    public User(String username, String password) {
        this.username = username;
        this.password = password;
    }

    public String getUsername() {
        return username;
    }

    public String getPassword() {
        return password;
    }
}

class Dish {
    private String name;
    private double price;
    private int count;

    public Dish(String name, double price) {
        this.name = name;
        this.price = price;
        this.count = 1;
    }

    public String getName() {
        return name;
    }

    public double getPrice() {
        return price;
    }

    public int getCount() {
        return count;
    }

    public void setCount(int count) {
        this.count = count;
    }
}

class Order {
    private ArrayList<Dish> dishes;
    private double totalPrice;
    private User user;

    public Order(ArrayList<Dish> dishes, double totalPrice, User user) {
        this.dishes = dishes;
        this.totalPrice = totalPrice;
        this.user = user;
    }

    public ArrayList<Dish> getDishes() {
        return dishes;
    }

    public double getTotalPrice() {
        return totalPrice;
    }

    public User getUser() {
        return user;
    }

    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder();
        sb.append("订单详情：\n");
        for (Dish dish : dishes) {
            sb.append(dish.getName()).append("（￥").append(dish.getPrice()).append("） x ").append(dish.getCount()).append("\n");
        }
        sb.append("总价：￥").append(totalPrice).append("\n");
        sb.append("用户：").append(user.getUsername()).append("\n");
        return sb.toString();
    }
}

这段代码实现了一个简单的Java订餐系统，包含了用户登录、菜品选择和订单管理等功能。当然，这只是一个简单的示例，实际的订餐系统需要更多的功能和细节处理。