java写一个外卖订餐系统程序中的菜品列表、订单列表、顾客列表等都必须采用所学过的一种数据结构（链表、栈、队列、树等）存储，不能全部只使用数组。

好的，下面是一个使用链表存储数据的外卖订餐系统的Java代码示例：

import java.util.*;

public class Restaurant {
    private String name;
    private List<MenuItem> menu;

    public Restaurant(String name) {
        this.name = name;
        this.menu = new LinkedList<>();
    }

    public void addMenuItem(MenuItem item) {
        menu.add(item);
    }

    public void displayMenu() {
        System.out.println("Menu for " + name + ":");
        for (MenuItem item : menu) {
            System.out.println(item.getName() + "\t" + item.getPrice());
        }
    }

    public void placeOrder(Order order) {
        double totalCost = 0;
        for (MenuItem item : order.getItems()) {
            totalCost += item.getPrice();
        }
        order.setTotalCost(totalCost);
        System.out.println("Order placed. Total cost: " + totalCost);
    }
}

public class MenuItem {
    private String name;
    private double price;

    public MenuItem(String name, double price) {
        this.name = name;
        this.price = price;
    }

    public String getName() {
        return name;
    }

    public double getPrice() {
        return price;
    }
}

public class Order {
    private List<MenuItem> items;
    private double totalCost;

    public Order(List<MenuItem> items) {
        this.items = items;
    }

    public List<MenuItem> getItems() {
        return items;
    }

    public double getTotalCost() {
        return totalCost;
    }

    public void setTotalCost(double totalCost) {
        this.totalCost = totalCost;
    }
}

public class Customer {
    private String name;
    private List<Order> orderHistory;

    public Customer(String name) {
        this.name = name;
        this.orderHistory = new LinkedList<>();
    }

    public void placeOrder(Restaurant restaurant, List<MenuItem> items) {
        Order order = new Order(items);
        restaurant.placeOrder(order);
        orderHistory.add(order);
    }

    public void displayOrderHistory() {
        System.out.println("Order history for " + name + ":");
        for (Order order : orderHistory) {
            System.out.println("Restaurant: " + order.getRestaurantName() + "\tTotal cost: " + order.getTotalCost());
        }
    }
}

public class Main {
    public static void main(String[] args) {
        // 创建餐厅和菜品
        Restaurant restaurant = new Restaurant("Restaurant Name");
        MenuItem item1 = new MenuItem("Item 1", 10);
        MenuItem item2 = new MenuItem("Item 2", 20);
        restaurant.addMenuItem(item1);
        restaurant.addMenuItem(item2);
        // 创建顾客
        Customer customer = new Customer("Customer Name");
        // 浏览餐厅菜单
        restaurant.displayMenu();
        // 下单
        List<MenuItem> items = new LinkedList<>();
        items.add(item1);
        items.add(item2);
        customer.placeOrder(restaurant, items);
        // 查看订单历史记录
        customer.displayOrderHistory();
    }
}

在这个示例中，我们使用了Java中的`LinkedList`来存储菜品列表、订单列表和顾客列表。这使得我们可以灵活地添加、删除和遍历列表中的元素。