tadas-subonis

 class Customer {
            String name;
        }

        class Order {
            String orderId;
            Customer customer;
        }

tadas-subonis

    public static void main(String... args) {
        class Customer {
            String name;
        }

        class Order {
            String orderId;
            Customer customer;
        }

tadas-subonis

        class Customer {
            String name;
        }

        class Order {
            String orderId;
            Customer customer;
        }

tadas-subonis

        class Customer {
            String name;
        }

        class Order {
            String orderId;
            Customer customer;
        }

tadas-subonis

class OrderManager {
            double getTotalPrice(Order order) {
                //...
                for (Item item : order.getItems()) {
                    //...
                }
                return num;
            }
        }

tadas-subonis

        class OrderManager {
            double getTotalPrice(Order order) {
                //...
                for (Item item : order.getItems()) {
                    //...
                }
                return num;
            }
        }

tadas-subonis

        class Order {
            Item[] items;
            String orderId;
            Customer customer;

            void addItem(Item item) {
            }

            double getTotalPrice() {
                //...

tadas-subonis

        class OrderManager {
            Map<Order, Double> prices;

            double getTotalPrice(Order order) {
                if (prices.containsKey(order)) {
                    return prices.get(order);
                }
                for (Item item : order.getItems()) {
                    //...
                }

tadas-subonis

        class Order {
            Item[] items;
            String orderId;
            Customer customer;
            Double totalPrice;

            void addItem(Item item) {
                //...
                totalPrice = null;
            }

tadas-subonis

        String orderId = request.getParam("id");
        String sku = request.getParam("sku");
        Order order = orderDao.findOneById(orderId);
        Item item = itemDao.findOneBySku(sku);

        order.addItem(item);

        double total = 0.0;
        for (Item item : order.getItems()) {
            total += item.getPrice();