Method addItem

StateDesignPattern/Inventory.java:31–43

(Item item, int codeNumber)

    }

    public void addItem(Item item, int codeNumber) throws Exception {

        for (ItemShelf itemShelf : itemShelves) {
            if (itemShelf.code == codeNumber) {
                if (itemShelf.isSoldOut()) {
                    itemShelf.item = item;
                    itemShelf.setSoldOut(false);
                } else {
                    throw new Exception("already item is present, you can not add item here");
                }
            }
        }
    }

    public Item getItem(int codeNumber) throws Exception {