It is the control point of the application. This is the class where the main interaction between the user and application takes place. It simply maintains the list of items which are added to the cart by the user. Its sole purpose is to store the purchased item into the cart, remove the item from the cart. It provides the user with all the required operations that a cart should have such as addToCart(), removeFromCart() etc… It also maintains a cartItemslist with a type Product, similar to the products list in products class. This is a concrete class which act as a cart to store the items temporarily into the cart. As we have provided the Product class inside the braces as new ArrayList(), this will tell the compiler that the list is of type Product and it can only contain an item which belongs to type Product. If you have read my previous article on Understanding Collections in JAVA then you will be familiar with the Generic Collection. As you can see, the initStoreItems() methods is used to add the products into a new ArrayList which is the type Product. In other words, this class is used to initialize your store as soon as the application is started. The role of this class in your shopping cart application is just to provide you with the store products. I have also override the Hash and Equals method in this class which you will realise later as we move forward. This is a concrete class which contains Product properties and provides setters and getters for it.

I will take each class one by one and explain the significance of each class. Classes Usedįor this example project, make sure all of the above-mentioned classes resides under the same package, i.e, collections.shoppingcart. For simplicity, all of the code will reside inside this package. Create the following package under your src folder,ģ. Firstly create a new Java Project with whatever name you like.Ģ. I have chosen Shopping Cart application for this purpose because I found it perfect for the situation and the use of collection in this application will help you better in modelling real world applications. If you have read my previous article which solely focused on getting you started with the JAVA Collections frameworkthen it’s time to dig a little deeper and create an application to demonstrate the use of Collections in real world application.

Online shopping code in java