DDD还是老式的？

// 领域模型
public class Order {
    private String orderId;
    private List<OrderItem> items;
    private BigDecimal totalAmount;

    // 省略构造函数和getter/setter
}

public class OrderItem {
    private String productId;
    private int quantity;
    private BigDecimal price;

    // 省略构造函数和getter/setter
}

// 领域服务
public class OrderService {
    public Order createOrder(List<OrderItem> items) {
        // 创建订单逻辑
        return new Order();
    }

    public Order getOrderById(String orderId) {
        // 查询订单逻辑
        return new Order();
    }
}

// 应用服务
public class OrderApplicationService {
    private OrderService orderService;

    public OrderApplicationService(OrderService orderService) {
        this.orderService = orderService;
    }

    public Order createOrder(List<OrderItem> items) {
        return orderService.createOrder(items);
    }

    public Order getOrderById(String orderId) {
        return orderService.getOrderById(orderId);
    }
}