JAVA shoppingcart

Design a shopping cart class. You can store a list of items in the shopping cart. Each item has its own specifications (i.e. code, name, ...). Each shopping cart is for a person. The method addTocart of shipping cart accepts an item as argument and adds that item to the cart and the method removeFromcart does it in reverse. 

You may need other classes to use them as internal complex type of your shopping cart. 

Create a class OnlineStore. This class has a method order summery, this method accepts the cart and information of the owner of the cart, sums up the prices, calculates the tax and shipping cost and produces an Order object, this object has a field totalPrice and a field owner of order.

Design a class CheckoutSystem. Each checkout system has a method checkout that accepts the order and a credit cart as arguments and checkouts the items. we don't care how internally this method works, the only task that it does right now is to produce a confirmation number and return it. Show the order summery.

Create a class OnlineOrderTestDrive. Create the main method inside. Inside your main method create a list of items and add them to a shopping cart object. Create an instance of the OnlineOrder class and call the orderSummery method of that class. Store the result in a variable. Create an instance of the CheckoutSystem and call the checkout method of that object. Show the confirmation message.

Note that there are internal classes that exist but I didn't mention them.

there is a example