🛒 E-Commerce Backend System

A Spring Boot backend project that handles the basic flow of an e-commerce application: users, products, cart management, order placement, payment status simulation, and order tracking.

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📌 About

This project is a backend-only e-commerce system built using Spring Boot, Spring Data JPA, Hibernate, and MySQL.

It allows users to add products to a cart, place orders, and track order/payment status through REST APIs.

User → Product → Cart → Order → Payment → Tracking

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✨ Features

• 👤 User management
• 📦 Product management
• 🛒 Add products to cart
• ❌ Remove cart items
• 🧾 Place orders
• 🚚 Track order status
• 💳 Simulate payment status
• 🗄️ MySQL database integration
• 📩 DTO-based request handling
• 🧩 Service interface and implementation structure

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🛠️ Tech Stack

• Java
• Spring Boot
• Spring Data JPA
• Hibernate
• MySQL
• Maven
• REST APIs
• Postman / Swagger

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📁 Project Structure

src/main/java/com.saish.ecommercebackend
│
├── controller
│   ├── CartController.java
│   ├── OrderController.java
│   ├── ProductController.java
│   └── UserController.java
│
├── dto
│   ├── CartRequest.java
│   ├── OrderStatusRequest.java
│   ├── ProductRequest.java
│   └── UserRequest.java
│
├── entity
│   ├── CartItem.java
│   ├── CustomerOrder.java
│   ├── OrderItem.java
│   ├── OrderStatus.java
│   ├── PaymentStatus.java
│   ├── Product.java
│   └── User.java
│
├── exception
│
├── repository
│   ├── CartItemRepository.java
│   ├── CustomerOrderRepository.java
│   ├── OrderItemRepository.java
│   ├── ProductRepository.java
│   └── UserRepository.java
│
├── service
│   ├── CartService.java
│   ├── OrderService.java
│   ├── ProductService.java
│   ├── UserService.java
│   └── impl
│       ├── CartServiceImpl.java
│       ├── OrderServiceImpl.java
│       ├── ProductServiceImpl.java
│       └── UserServiceImpl.java
│
└── EcommerceBackendApplication.java

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🔄 Application Flow

👤 User
  ↓
📦 Product
  ↓
🛒 Cart Item
  ↓
🧾 Customer Order
  ↓
📋 Order Item
  ↓
💳 Payment Status / 🚚 Order Status

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🏗️ Layered Architecture

Controller → Service → Repository → Database

Layer	Purpose
Controller	Handles API requests
DTO	Carries request data
Entity	Represents database tables
Repository	Talks to the database
Service	Contains business logic
Exception	Handles errors

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🧱 Main Entities

Entity	Purpose
User	Stores customer details
Product	Stores product details
CartItem	Stores products added to cart
CustomerOrder	Stores placed orders
OrderItem	Stores products inside an order
OrderStatus	Tracks order progress
PaymentStatus	Tracks payment state

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🚀 Future Improvements

• Add Spring Security and JWT
• Add admin/customer roles
• Add product categories
• Add search and filtering
• Add real payment gateway
• Add frontend integration
• Add unit tests

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