用java写餐饮管理系统

餐饮管理系统是一个复杂的系统，需要涉及到多个模块，包括菜单管理、订单管理、库存管理、员工管理等。以下是一个简单的餐饮管理系统的Java代码示例。

首先，我们需要定义一些基本的实体类：

public class Food {
    private int id;
    private String name;
    private double price;

    public Food(int id, String name, double price) {
        this.id = id;
        this.name = name;
        this.price = price;
    }

    // getters and setters
}

public class Order {
    private int id;
    private List<Food> foods;
    private double total;

    public Order(int id, List<Food> foods, double total) {
        this.id = id;
        this.foods = foods;
        this.total = total;
    }

    // getters and setters
}

public class Employee {
    private int id;
    private String name;
    private String position;

    public Employee(int id, String name, String position) {
        this.id = id;
        this.name = name;
        this.position = position;
    }

    // getters and setters
}

public class Inventory {
    private int id;
    private Food food;
    private int quantity;

    public Inventory(int id, Food food, int quantity) {
        this.id = id;
        this.food = food;
        this.quantity = quantity;
    }

    // getters and setters
}

然后，我们需要实现各个模块的功能，例如：

public class MenuManager {
    private List<Food> foods;

    public MenuManager() {
        this.foods = new ArrayList<>();
    }

    public void addFood(Food food) {
        this.foods.add(food);
    }

    public void removeFood(Food food) {
        this.foods.remove(food);
    }

    public List<Food> getFoods() {
        return this.foods;
    }
}

public class OrderManager {
    private List<Order> orders;

    public OrderManager() {
        this.orders = new ArrayList<>();
    }

    public void addOrder(Order order) {
        this.orders.add(order);
    }

    public void removeOrder(Order order) {
        this.orders.remove(order);
    }

    public List<Order> getOrders() {
        return this.orders;
    }
}

public class InventoryManager {
    private List<Inventory> inventories;

    public InventoryManager() {
        this.inventories = new ArrayList<>();
    }

    public void addInventory(Inventory inventory) {
        this.inventories.add(inventory);
    }

    public void removeInventory(Inventory inventory) {
        this.inventories.remove(inventory);
    }

    public List<Inventory> getInventories() {
        return this.inventories;
    }

    public int getInventoryQuantity(Food food) {
        for (Inventory inventory : this.inventories) {
            if (inventory.getFood().equals(food)) {
                return inventory.getQuantity();
            }
        }
        return 0;
    }

    public void updateInventoryQuantity(Food food, int quantity) {
        for (Inventory inventory : this.inventories) {
            if (inventory.getFood().equals(food)) {
                inventory.setQuantity(quantity);
            }
        }
    }
}

public class EmployeeManager {
    private List<Employee> employees;

    public EmployeeManager() {
        this.employees = new ArrayList<>();
    }

    public void addEmployee(Employee employee) {
        this.employees.add(employee);
    }

    public void removeEmployee(Employee employee) {
        this.employees.remove(employee);
    }

    public List<Employee> getEmployees() {
        return this.employees;
    }
}

最后，我们可以编写一个简单的主程序来模拟餐饮管理系统的使用：

public class RestaurantMain {
    public static void main(String[] args) {
        // 初始化菜单
        MenuManager menuManager = new MenuManager();
        menuManager.addFood(new Food(1, "烤鸭", 88.0));
        menuManager.addFood(new Food(2, "糖醋排骨", 38.0));
        menuManager.addFood(new Food(3, "宫保鸡丁", 28.0));

        // 初始化库存
        InventoryManager inventoryManager = new InventoryManager();
        inventoryManager.addInventory(new Inventory(1, menuManager.getFoods().get(0), 10));
        inventoryManager.addInventory(new Inventory(2, menuManager.getFoods().get(1), 20));
        inventoryManager.addInventory(new Inventory(3, menuManager.getFoods().get(2), 30));

        // 初始化员工
        EmployeeManager employeeManager = new EmployeeManager();
        employeeManager.addEmployee(new Employee(1, "张三", "服务员"));
        employeeManager.addEmployee(new Employee(2, "李四", "厨师"));

        // 模拟点餐流程
        List<Food> foods = new ArrayList<>();
        foods.add(menuManager.getFoods().get(0));
        foods.add(menuManager.getFoods().get(1));
        Order order = new Order(1, foods, 126.0);
        inventoryManager.updateInventoryQuantity(menuManager.getFoods().get(0), inventoryManager.getInventoryQuantity(menuManager.getFoods().get(0)) - 1);
        inventoryManager.updateInventoryQuantity(menuManager.getFoods().get(1), inventoryManager.getInventoryQuantity(menuManager.getFoods().get(1)) - 1);
        employeeManager.getEmployees().get(0).takeOrder(order);
        employeeManager.getEmployees().get(1).prepareFood(order);

        // 模拟结账流程
        employeeManager.getEmployees().get(0).checkout(order);
    }
}

当然，这只是一个简单的示例，实际的餐饮管理系统要比这个复杂得多。但是，通过这个示例，您可以了解到如何使用Java编写一个基本的餐饮管理系统。