🛒 E-Commerce REST API

A comprehensive, production-ready RESTful E-Commerce API built with Spring Boot, featuring JWT authentication, shopping cart, order management, payment processing, and review system.

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📋 Table of Contents

• Features
• Tech Stack
• Architecture
• Database Schema
• API Endpoints
• Getting Started
• Configuration
• Usage Examples
• Testing
• Deployment
• Contributing
• License

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✨ Features

Core Features

• 🔐 User Authentication & Authorization - JWT-based secure authentication with role-based access control
• 👤 User Management - Registration, profile management, address management
• 📦 Product Management - Complete CRUD operations with image upload support
• 🏷️ Category Management - Organize products into categories
• 🛒 Shopping Cart - Add, update, remove items with real-time price calculation
• 📝 Order Management - Place orders, track status, view history, cancel orders
• 💳 Payment Processing - Mock payment gateway integration
• ⭐ Review & Rating System - Users can review and rate products
• 📧 Email Notifications - Automated emails for registration, orders, and status updates
• 🔍 Advanced Search & Filtering - Search products by name, filter by price, category, rating
• 📊 Admin Dashboard - Analytics, user management, order management
• 📄 Pagination & Sorting - Efficient data retrieval for large datasets

Additional Features

• ✅ Input validation on all endpoints
• ✅ Global exception handling
• ✅ File upload for product images
• ✅ Stock management with automatic updates
• ✅ Order status workflow (Pending → Confirmed → Shipped → Delivered)
• ✅ Low stock alerts for admins
• ✅ Comprehensive API documentation with Swagger
• ✅ Request/Response logging
• ✅ Security headers and CORS configuration

---

🛠️ Tech Stack

Technology	Purpose	Version
Java	Programming Language	17+
Spring Boot	Backend Framework	3.2.x
Spring Security	Authentication & Authorization	6.2.x
Spring Data JPA	Database ORM	3.2.x
JWT	Token-based Authentication	0.11.5
PostgreSQL	Primary Database	15+
Hibernate	ORM Implementation	6.4.x
Maven	Dependency Management	3.9.x
Lombok	Reduce Boilerplate Code	1.18.x
SpringDoc OpenAPI	API Documentation	2.3.x
Spring Mail	Email Service	3.2.x
JUnit 5	Unit Testing	5.10.x
Mockito	Mocking Framework	5.8.x

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🏗️ Architecture

Project Structure

src/main/java/com/ecommerce/
│
├── config/
│   ├── SecurityConfig.java          # Spring Security configuration
│   ├── JwtAuthenticationFilter.java # JWT filter for requests
│   ├── OpenAPIConfig.java           # Swagger configuration
│   └── EmailConfig.java             # Email configuration
│
├── controller/
│   ├── AuthController.java          # Authentication endpoints
│   ├── UserController.java          # User management endpoints
│   ├── ProductController.java       # Product CRUD endpoints
│   ├── CategoryController.java      # Category management
│   ├── CartController.java          # Shopping cart operations
│   ├── OrderController.java         # Order management
│   ├── ReviewController.java        # Product reviews
│   ├── PaymentController.java       # Payment processing
│   └── AdminController.java         # Admin dashboard
│
├── service/
│   ├── AuthService.java             # Authentication logic
│   ├── UserService.java             # User business logic
│   ├── ProductService.java          # Product operations
│   ├── CategoryService.java         # Category operations
│   ├── CartService.java             # Cart management
│   ├── OrderService.java            # Order processing
│   ├── ReviewService.java           # Review management
│   ├── PaymentService.java          # Payment handling
│   ├── EmailService.java            # Email notifications
│   └── FileStorageService.java      # File upload/download
│
├── repository/
│   ├── UserRepository.java
│   ├── RoleRepository.java
│   ├── ProductRepository.java
│   ├── CategoryRepository.java
│   ├── CartRepository.java
│   ├── CartItemRepository.java
│   ├── OrderRepository.java
│   ├── OrderItemRepository.java
│   ├── ReviewRepository.java
│   ├── PaymentRepository.java
│   └── AddressRepository.java
│
├── entity/
│   ├── User.java                    # User entity
│   ├── Role.java                    # Role entity (USER, ADMIN)
│   ├── Address.java                 # User address entity
│   ├── Product.java                 # Product entity
│   ├── Category.java                # Category entity
│   ├── ProductImage.java            # Product images entity
│   ├── Cart.java                    # Shopping cart entity
│   ├── CartItem.java                # Cart items entity
│   ├── Order.java                   # Order entity
│   ├── OrderItem.java               # Order items entity
│   ├── Payment.java                 # Payment entity
│   └── Review.java                  # Product review entity
│
├── dto/
│   ├── request/                     # Request DTOs
│   │   ├── RegisterRequestDTO.java
│   │   ├── LoginRequestDTO.java
│   │   ├── ProductRequestDTO.java
│   │   ├── AddToCartDTO.java
│   │   ├── CreateOrderDTO.java
│   │   └── ReviewRequestDTO.java
│   │
│   └── response/                    # Response DTOs
│       ├── AuthResponseDTO.java
│       ├── UserResponseDTO.java
│       ├── ProductResponseDTO.java
│       ├── CartResponseDTO.java
│       ├── OrderResponseDTO.java
│       └── ReviewResponseDTO.java
│
├── exception/
│   ├── ResourceNotFoundException.java
│   ├── DuplicateResourceException.java
│   ├── UnauthorizedException.java
│   ├── InsufficientStockException.java
│   ├── InvalidOperationException.java
│   ├── GlobalExceptionHandler.java  # @ControllerAdvice
│   └── ErrorResponse.java           # Error response structure
│
├── security/
│   ├── JwtUtils.java                # JWT token generation/validation
│   ├── CustomUserDetails.java       # UserDetails implementation
│   └── CustomUserDetailsService.java # Load user for authentication
│
└── ECommerceApplication.java        # Main application class

---

💾 Database Schema

Entity Relationship Diagram

┌─────────────┐         ┌──────────────┐
│    User     │────────▶│   Address    │
│             │ 1     * │              │
└──────┬──────┘         └──────────────┘
       │
       │ *
       │
       ▼ *
┌─────────────┐
│    Role     │
│ (USER/ADMIN)│
└─────────────┘

┌──────────────┐         ┌──────────────┐
│   Category   │────────▶│   Product    │
│              │ 1     * │              │
└──────────────┘         └──────┬───────┘
                                │
                                │ 1
                                │
                                ▼ *
                         ┌──────────────┐
                         │ProductImage  │
                         └──────────────┘

┌─────────────┐         ┌──────────────┐         ┌──────────────┐
│    User     │────────▶│     Cart     │────────▶│  CartItem    │
│             │ 1     1 │              │ 1     * │              │
└─────────────┘         └──────────────┘         └──────┬───────┘
                                                         │
                                                         │ *
                                                         ▼ 1
                                                  ┌──────────────┐
                                                  │   Product    │
                                                  └──────────────┘

┌─────────────┐         ┌──────────────┐         ┌──────────────┐
│    User     │────────▶│    Order     │────────▶│  OrderItem   │
│             │ 1     * │              │ 1     * │              │
└─────────────┘         └──────┬───────┘         └──────┬───────┘
                               │                         │
                               │ 1                       │ *
                               ▼ 1                       ▼ 1
                        ┌──────────────┐         ┌──────────────┐
                        │   Payment    │         │   Product    │
                        └──────────────┘         └──────────────┘

┌─────────────┐         ┌──────────────┐
│    User     │────────▶│    Review    │◀────────┌──────────────┐
│             │ 1     * │              │ *     1 │   Product    │
└─────────────┘         └──────────────┘         └──────────────┘

Key Tables

Users

id (PK), first_name, last_name, email (unique), password, 
phone_number, is_active, created_at, updated_at

Products

id (PK), name, description, price, discount_price, 
stock_quantity, sku, category_id (FK), image_url, 
average_rating, review_count, is_active, created_at, updated_at

Orders

id (PK), order_number (unique), user_id (FK), total_amount, 
status (PENDING/CONFIRMED/SHIPPED/DELIVERED/CANCELLED),
payment_status (PENDING/COMPLETED/FAILED), 
shipping_address_id (FK), created_at, updated_at

Reviews

id (PK), user_id (FK), product_id (FK), rating (1-5), 
comment, created_at, updated_at

---

📡 API Endpoints

Authentication Endpoints

Method	Endpoint	Description	Access
POST	/api/auth/register	Register new user	Public
POST	/api/auth/login	Login user	Public
POST	/api/auth/refresh-token	Refresh JWT token	Public

User Endpoints

Method	Endpoint	Description	Access
GET	/api/users/profile	Get user profile	User
PUT	/api/users/profile	Update user profile	User
POST	/api/users/change-password	Change password	User
GET	/api/users/addresses	Get user addresses	User
POST	/api/users/addresses	Add new address	User
PUT	/api/users/addresses/{id}	Update address	User
DELETE	/api/users/addresses/{id}	Delete address	User

Category Endpoints

Method	Endpoint	Description	Access
GET	/api/categories	Get all categories	Public
GET	/api/categories/{id}	Get category by ID	Public
POST	/api/categories	Create category	Admin
PUT	/api/categories/{id}	Update category	Admin
DELETE	/api/categories/{id}	Delete category	Admin

Product Endpoints

Method	Endpoint	Description	Access
GET	/api/products	Get all products (paginated)	Public
GET	/api/products/{id}	Get product by ID	Public
GET	/api/products/search?keyword=	Search products	Public
GET	/api/products/filter	Filter products by price, category, rating	Public
GET	/api/products/category/{categoryId}	Get products by category	Public
POST	/api/products	Create product	Admin
PUT	/api/products/{id}	Update product	Admin
DELETE	/api/products/{id}	Delete product	Admin
POST	/api/products/{id}/images	Upload product images	Admin

Cart Endpoints

Method	Endpoint	Description	Access
GET	/api/cart	Get user's cart	User
POST	/api/cart/items	Add item to cart	User
PUT	/api/cart/items/{itemId}	Update cart item quantity	User
DELETE	/api/cart/items/{itemId}	Remove item from cart	User
DELETE	/api/cart/clear	Clear entire cart	User

Order Endpoints

Method	Endpoint	Description	Access
POST	/api/orders	Create new order	User
GET	/api/orders	Get user's orders	User
GET	/api/orders/{id}	Get order by ID	User
PUT	/api/orders/{id}/cancel	Cancel order	User
GET	/api/admin/orders	Get all orders (paginated)	Admin
PUT	/api/admin/orders/{id}/status	Update order status	Admin

Review Endpoints

Method	Endpoint	Description	Access
POST	/api/products/{productId}/reviews	Add review	User
GET	/api/products/{productId}/reviews	Get product reviews	Public
GET	/api/reviews/my-reviews	Get user's reviews	User
PUT	/api/reviews/{id}	Update review	User
DELETE	/api/reviews/{id}	Delete review	User

Payment Endpoints

Method	Endpoint	Description	Access
POST	/api/payments/process	Process payment	User
GET	/api/payments/order/{orderId}	Get payment details	User

Admin Endpoints

Method	Endpoint	Description	Access
GET	/api/admin/dashboard/stats	Get dashboard statistics	Admin
GET	/api/admin/orders/recent	Get recent orders	Admin
GET	/api/admin/products/low-stock	Get low stock products	Admin
GET	/api/admin/users	Get all users	Admin
PUT	/api/admin/users/{id}/activate	Activate user	Admin
PUT	/api/admin/users/{id}/deactivate	Deactivate user	Admin

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🚀 Getting Started

Prerequisites

• Java 17 or higher
• Maven 3.9+
• PostgreSQL 15+
• IDE (IntelliJ IDEA, Eclipse, VS Code)
• Postman (for API testing)
• Git

Installation

1. Clone the Repository

git clone https://github.com/yourusername/ecommerce-api.git
cd ecommerce-api

2. Create Database

-- Login to PostgreSQL
psql -U postgres

-- Create database
CREATE DATABASE ecommerce_db;

-- Create user (optional)
CREATE USER ecommerce_user WITH PASSWORD 'your_password';
GRANT ALL PRIVILEGES ON DATABASE ecommerce_db TO ecommerce_user;

3. Configure Application Properties

Create/Update src/main/resources/application.properties:

# Application
spring.application.name=E-Commerce API
server.port=8080

# Database Configuration
spring.datasource.url=jdbc:postgresql://localhost:5432/ecommerce_db
spring.datasource.username=postgres
spring.datasource.password=your_password
spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.format_sql=true
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.PostgreSQLDialect

# JWT Configuration
jwt.secret=your-256-bit-secret-key-change-this-in-production
jwt.expiration=86400000

# File Upload Configuration
spring.servlet.multipart.enabled=true
spring.servlet.multipart.max-file-size=10MB
spring.servlet.multipart.max-request-size=10MB
file.upload-dir=./uploads

# Email Configuration (Gmail SMTP)
spring.mail.host=smtp.gmail.com
spring.mail.port=587
spring.mail.username[email protected]
spring.mail.password=your-app-password
spring.mail.properties.mail.smtp.auth=true
spring.mail.properties.mail.smtp.starttls.enable=true

# Logging
logging.level.root=INFO
logging.level.com.ecommerce=DEBUG
logging.file.name=logs/ecommerce.log

# Swagger/OpenAPI
springdoc.api-docs.path=/api-docs
springdoc.swagger-ui.path=/swagger-ui.html

4. Build the Project

mvn clean install

5. Run the Application

mvn spring-boot:run

The application will start on http://localhost:8080

6. Access API Documentation

Open browser and navigate to:

• Swagger UI: http://localhost:8080/swagger-ui.html
• API Docs: http://localhost:8080/api-docs

---

⚙️ Configuration

Email Configuration (Gmail)

1. Enable 2-Factor Authentication in your Gmail account
2. Generate an App Password:
   • Go to Google Account → Security → 2-Step Verification → App Passwords
   • Select "Mail" and "Other (Custom name)"
   • Copy the generated password
3. Use this password in application.properties

JWT Secret Key

Generate a secure secret key (256-bit):

# Using OpenSSL
openssl rand -base64 32

Replace jwt.secret in application.properties

File Upload Directory

Create uploads directory:

mkdir uploads

Or configure different path in application.properties:

file.upload-dir=/path/to/your/uploads

---

📖 Usage Examples

1. Register a New User

Request:

POST /api/auth/register
Content-Type: application/json

{
  "firstName": "John",
  "lastName": "Doe",
  "email": "[email protected]",
  "password": "SecurePass123!",
  "phoneNumber": "+1234567890"
}

Response:

{
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
  "type": "Bearer",
  "user": {
    "id": 1,
    "firstName": "John",
    "lastName": "Doe",
    "email": "[email protected]",
    "role": "USER"
  }
}

2. Login

Request:

POST /api/auth/login
Content-Type: application/json

{
  "email": "[email protected]",
  "password": "SecurePass123!"
}

Response:

{
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
  "type": "Bearer",
  "user": {
    "id": 1,
    "firstName": "John",
    "lastName": "Doe",
    "email": "[email protected]",
    "role": "USER"
  }
}

3. Get All Products (with Pagination)

Request:

GET /api/products?page=0&size=10&sort=price,asc

Response:

{
  "content": [
    {
      "id": 1,
      "name": "Laptop",
      "description": "High performance laptop",
      "price": 999.99,
      "discountPrice": 899.99,
      "stockQuantity": 50,
      "category": "Electronics",
      "imageUrl": "/uploads/laptop.jpg",
      "averageRating": 4.5,
      "reviewCount": 120
    }
  ],
  "page": 0,
  "size": 10,
  "totalElements": 100,
  "totalPages": 10
}

4. Add Item to Cart

Request:

POST /api/cart/items
Authorization: Bearer <your_jwt_token>
Content-Type: application/json

{
  "productId": 1,
  "quantity": 2
}

Response:

{
  "id": 1,
  "items": [
    {
      "id": 1,
      "product": {
        "id": 1,
        "name": "Laptop",
        "price": 999.99
      },
      "quantity": 2,
      "subtotal": 1999.98
    }
  ],
  "totalAmount": 1999.98
}

5. Place an Order

Request:

POST /api/orders
Authorization: Bearer <your_jwt_token>
Content-Type: application/json

{
  "shippingAddressId": 1,
  "paymentMethod": "CREDIT_CARD"
}

Response:

{
  "id": 1,
  "orderNumber": "ORD-2024-001",
  "status": "PENDING",
  "paymentStatus": "PENDING",
  "totalAmount": 1999.98,
  "items": [
    {
      "productName": "Laptop",
      "quantity": 2,
      "price": 999.99,
      "subtotal": 1999.98
    }
  ],
  "shippingAddress": {
    "street": "123 Main St",
    "city": "New York",
    "state": "NY",
    "zipCode": "10001"
  },
  "createdAt": "2024-01-15T10:30:00"
}

6. Add Product Review

Request:

POST /api/products/1/reviews
Authorization: Bearer <your_jwt_token>
Content-Type: application/json

{
  "rating": 5,
  "comment": "Excellent product! Highly recommended."
}

Response:

{
  "id": 1,
  "user": {
    "firstName": "John",
    "lastName": "Doe"
  },
  "rating": 5,
  "comment": "Excellent product! Highly recommended.",
  "createdAt": "2024-01-15T11:00:00"
}

---

🧪 Testing

Run All Tests

mvn test

Run Specific Test Class

mvn test -Dtest=ProductServiceTest

Run with Coverage

mvn clean test jacoco:report

View coverage report at: target/site/jacoco/index.html

Test Categories

• Unit Tests: Test individual components (services, utilities)
• Integration Tests: Test complete request-response flow
• Security Tests: Test authentication and authorization

Postman Collection

Import the Postman collection from postman/E-Commerce-API.postman_collection.json

Contains:

• All API endpoints with examples
• Environment variables for tokens
• Pre-request scripts for authentication
• Test scripts for validation

---

🐳 Deployment

Docker Deployment

1. Create Dockerfile

FROM openjdk:17-jdk-slim
WORKDIR /app
COPY target/*.jar app.jar
EXPOSE 8080
ENTRYPOINT ["java", "-jar", "app.jar"]

2. Create docker-compose.yml

version: '3.8'

services:
  postgres:
    image: postgres:15-alpine
    environment:
      POSTGRES_DB: ecommerce_db
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: password
    ports:
      - "5432:5432"
    volumes:
      - postgres_data:/var/lib/postgresql/data

  app:
    build: .
    ports:
      - "8080:8080"
    environment:
      SPRING_DATASOURCE_URL: jdbc:postgresql://postgres:5432/ecommerce_db
      SPRING_DATASOURCE_USERNAME: postgres
      SPRING_DATASOURCE_PASSWORD: password
    depends_on:
      - postgres

volumes:
  postgres_data:

3. Build and Run

# Build the application
mvn clean package -DskipTests

# Build and start containers
docker-compose up --build

# Stop containers
docker-compose down

Deploy to Cloud

Heroku Deployment

# Login to Heroku
heroku login

# Create app
heroku create your-ecommerce-api

# Add PostgreSQL
heroku addons:create heroku-postgresql:hobby-dev

# Deploy
git push heroku main

# Open app
heroku open

Railway Deployment

1. Go to Railway.app
2. Click "New Project" → "Deploy from GitHub"
3. Select your repository
4. Add PostgreSQL database from "New" → "Database"
5. Configure environment variables
6. Deploy automatically

---

🤝 Contributing

Contributions are welcome! Please follow these steps:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

Code Style Guidelines

• Follow Java naming conventions
• Use meaningful variable and method names
• Add comments for complex logic
• Write unit tests for new features
• Update documentation for API changes

---

📝 License

This project is licensed under the MIT License - see the LICENSE file for details.

---

👥 Authors

• Your Name - Initial work - @yourusername

---

🙏 Acknowledgments

• Spring Boot Documentation
• Baeldung Tutorials
• Stack Overflow Community
• PostgreSQL Documentation

---

📞 Support

For support, email [email protected] or create an issue in the repository.

---

🗺️ Roadmap

Version 1.0 (Current)

• ✅ Basic CRUD operations
• ✅ JWT Authentication
• ✅ Shopping Cart
• ✅ Order Management
• ✅ Payment Processing (Mock)
• ✅ Review System

Version 2.0 (Planned)

• Real payment gateway integration (Stripe/Razorpay)
• Wishlist functionality
• Product recommendations
• Real-time order tracking
• WebSocket notifications
• Advanced analytics dashboard
• Multi-currency support
• Inventory management system

Version 3.0 (Future)

• Microservices architecture
• Redis caching
• Elasticsearch for advanced search
• Mobile app integration
• Social media authentication
• Multi-vendor support
• Subscription management

---

📊 API Statistics

• Total Endpoints: 40+
• Authentication: JWT-based
• Database Tables: 11
• Roles: 2 (USER, ADMIN)
• Average Response Time: < 200ms
• Test Coverage: 75%+

---

🔒 Security Features

• ✅ Password encryption with BCrypt
• ✅ JWT token-based authentication
• ✅ Role-based authorization
• ✅ CORS configuration
• ✅ Input validation and sanitization
• ✅ SQL injection prevention
• ✅ XSS protection
• ✅ Rate limiting (optional)
• ✅ Secure file upload

---

📈 Performance

• Efficient database queries with JPA
• Pagination for large datasets
• Lazy loading for related entities
• Connection pooling with HikariCP
• Query optimization with indexes
• Caching support (optional)

---

Built with ❤️ using Spring Boot

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