java 模拟库存管理系统

一个简单的 Java 模拟库存管理系统可能包括以下基本功能：

1. 商品信息管理：包括商品名称、编号、进价、售价、库存数量等。

2. 订单管理：可以添加、修改、查询订单信息，包括订单号、下单时间、客户信息、商品信息、订单金额等。

3. 库存管理：可以实时查询某个商品的库存数量，当订单完成后，需要更新库存数量。

4. 报表管理：可以生成各种报表，比如销售报表、进货报表、库存报表等，用于帮助管理员掌握经营情况。

下面是一个简单的库存管理系统的示例代码：

import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Scanner;

public class InventoryManagementSystem {
    private List<Product> products = new ArrayList<>();
    private List<Order> orders = new ArrayList<>();

    public void addProduct(Product product) {
        products.add(product);
    }

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

    public void printInventoryReport() {
        System.out.println("Inventory Report:");
        for (Product product : products) {
            System.out.println(product.getName() + ", " + product.getQuantity());
        }
    }

    public void printSalesReport(Date startDate, Date endDate) {
        System.out.println("Sales Report from " + startDate + " to " + endDate + ":");
        double totalSales = 0;
        for (Order order : orders) {
            if (order.getOrderDate().after(startDate) && order.getOrderDate().before(endDate)) {
                System.out.println(order.getOrderNumber() + ", " + order.getOrderDate() + ", " + order.getCustomerName() + ", " + order.getTotalPrice());
                totalSales += order.getTotalPrice();
            }
        }
        System.out.println("Total sales: " + totalSales);
    }

    public static void main(String[] args) {
        InventoryManagementSystem system = new InventoryManagementSystem();
        Scanner scanner = new Scanner(System.in);

        while (true) {
            System.out.println("1. Add product");
            System.out.println("2. Add order");
            System.out.println("3. Print inventory report");
            System.out.println("4. Print sales report");
            System.out.println("5. Exit");
            System.out.print("Select an option: ");
            int option = scanner.nextInt();

            switch (option) {
                case 1:
                    System.out.print("Enter product name: ");
                    String name = scanner.next();
                    System.out.print("Enter product quantity: ");
                    int quantity = scanner.nextInt();
                    Product product = new Product(name, quantity);
                    system.addProduct(product);
                    System.out.println("Product added successfully.");
                    break;
                case 2:
                    System.out.print("Enter order number: ");
                    int orderNumber = scanner.nextInt();
                    System.out.print("Enter customer name: ");
                    String customerName = scanner.next();
                    Order order = new Order(orderNumber, new Date(), customerName);
                    while (true) {
                        System.out.print("Enter product name (or 'q' to quit): ");
                        String productName = scanner.next();
                        if (productName.equals("q")) {
                            break;
                        }
                        System.out.print("Enter quantity: ");
                        int orderQuantity = scanner.nextInt();
                        Product orderedProduct = system.products.stream().filter(p -> p.getName().equals(productName)).findFirst().orElse(null);
                        if (orderedProduct == null) {
                            System.out.println("Product not found.");
                        } else if (orderedProduct.getQuantity() < orderQuantity) {
                            System.out.println("Insufficient quantity in stock.");
                        } else {
                            order.addOrderItem(new OrderItem(orderedProduct, orderQuantity));
                            orderedProduct.setQuantity(orderedProduct.getQuantity() - orderQuantity);
                        }
                    }
                    system.addOrder(order);
                    System.out.println("Order added successfully.");
                    break;
                case 3:
                    system.printInventoryReport();
                    break;
                case 4:
                    System.out.print("Enter start date (yyyy-mm-dd): ");
                    String startDateString = scanner.next();
                    System.out.print("Enter end date (yyyy-mm-dd): ");
                    String endDateString = scanner.next();
                    Date startDate = java.sql.Date.valueOf(startDateString);
                    Date endDate = java.sql.Date.valueOf(endDateString);
                    system.printSalesReport(startDate, endDate);
                    break;
                case 5:
                    System.out.println("Exiting...");
                    System.exit(0);
                default:
                    System.out.println("Invalid option.");
            }
        }
    }
}

class Product {
    private String name;
    private int quantity;

    public Product(String name, int quantity) {
        this.name = name;
        this.quantity = quantity;
    }

    public String getName() {
        return name;
    }

    public int getQuantity() {
        return quantity;
    }

    public void setQuantity(int quantity) {
        this.quantity = quantity;
    }
}

class Order {
    private int orderNumber;
    private Date orderDate;
    private String customerName;
    private List<OrderItem> orderItems = new ArrayList<>();

    public Order(int orderNumber, Date orderDate, String customerName) {
        this.orderNumber = orderNumber;
        this.orderDate = orderDate;
        this.customerName = customerName;
    }

    public int getOrderNumber() {
        return orderNumber;
    }

    public Date getOrderDate() {
        return orderDate;
    }

    public String getCustomerName() {
        return customerName;
    }

    public List<OrderItem> getOrderItems() {
        return orderItems;
    }

    public double getTotalPrice() {
        double totalPrice = 0;
        for (OrderItem orderItem : orderItems) {
            totalPrice += orderItem.getProduct().getPrice() * orderItem.getQuantity();
        }
        return totalPrice;
    }

    public void addOrderItem(OrderItem orderItem) {
        orderItems.add(orderItem);
    }
}

class OrderItem {
    private Product product;
    private int quantity;

    public OrderItem(Product product, int quantity) {
        this.product = product;
        this.quantity = quantity;
    }

    public Product getProduct() {
        return product;
    }

    public int getQuantity() {
        return quantity;
    }
}

这个例子实现了一个简单的控制台界面，可以通过不同的选项添加商品、添加订单、打印库存报告、打印销售报告等。当用户添加订单时，系统会自动更新库存数量。