sidmishraw/simpleestore

Simple EStore simulation for objects as states

EStore

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Author: Sidharth Mishra

Version: 0.0.1

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Note: All objects made explicitly by me are Value objects. These include Customer, ShoppingCart, Item, CartState, EStore and EStoreDriver.

Note: This project too follows similar restrictions as FJava but not that strictly. The variables are not active.

Briefing:

In this example, EStore is an e-store maintaining a large collection of shopping carts.

Each shopping cart has a customer, contains items and has a status: BOOKED, PURCHASED, SHIPPED.

The items can be added and removed to/from the shopping cart.

The EStore maintains a hash-map indexed by the shopping carts. Each cart is associated with its state.

Each time the state of the cart changes (items are added/removed, status changes) the old binding is deleted and a new binding is created that associates the same cart to the new state.

Class Summary:

The project has the following classes:

• Customer: This is the customer. It is a value object.

• Item: This is an item. It is a value object.

• CartStatus: This is all the possible statuses of the shopping cart. It is an enum with values BOOKED, PURCHASED, SHIPPED

• ShoppingCart: This is the shopping cart. It has a cartId and customer. It is a value object. Used as the key in the hash map called shoppingCarts in EStore.java. The hashmap is a mapping between the shopping cart and its state.

• CartState: This represents the cart's state. The state of a cart is defined as the list of items it holds and it's status. This is a value object.

• EStore: This represents the e-store. It has the hashmap holding the mapping from the ShoppingCart to the CartState. It also exposes the makeCart, addItem, removeItem and changeStatus functionalities.

• EStoreDriver: This is the main driver code. It is the running example of this concept.

Tools:

• Java -- JDK v1.8.0_131
• Eclipse Neon.3 v4.6.3