E-Commerce System (Java)

This repository contains a Java-based implementation of a simplified e-commerce system that supports key features such as product expiration, shipping management, cart operations, and checkout processing — all designed using clean Object-Oriented Programming principles.

Features

• Product Management

  • Define products with name, price, quantity
  • Support for:
    • Expirable products (e.g., Cheese)
    • Shippable products with weight (e.g., TV, Cheese)
    • Non-expirable/non-shippable items (e.g., Mobile Scratch Cards)

• Cart System

  • Add items to the cart with a specific quantity
  • Prevent adding expired or out-of-stock items

• Checkout Process

  • Validate customer balance
  • Calculate:
    • Subtotal
    • Shipping fee (based on total weight at 30 EGP/kg)
    • Final paid amount
  • Deduct balance and reduce product stock
  • Print:
    • Shipment notice
    • Checkout receipt

• Shipping Logic

  • Interfaces ensure that only eligible products implement Shippable
  • Automatically collects and processes shippable items for shipping service

Design & Structure

• Product is an abstract base class for all product types.
• Shippable and Expirable are marker interfaces for optional behavior.
• Concrete products (Cheese, TV, MobileScratchCard) implement relevant interfaces.
• Cart and CartItem manage purchase operations.
• Customer holds balance and handles payment.
• ShippingService and CheckoutService encapsulate business rules.
• ECommerceApp acts as the composition root for wiring and executing the use case.

Technologies

• Language: Java 8+
• No external libraries
• Pure Object-Oriented Programming

How to Use

1. Clone the Repository

Clone the repository to your local machine:

  git clone https://github.com/AhmedAmgadElsharkawy/ecommerce-system-java.git

2. run the application

  java src/ECommerceSystem.java

License

This project is open-source and available under the MIT Licence.