Billing Software Backend

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🚀 Overview

A fully-featured billing software backend built with Spring Boot, JPA/Hibernate, and AWS S3 integration. This project provides a robust API for managing categories, items, orders, payments, and users with JWT-based authentication, Razorpay integration, and file uploads.

Key Features

✅ User Authentication – Secure login with JWT tokens ✅ Category & Item Management – CRUD operations with file uploads ✅ Order Processing – Create, fetch, and delete orders ✅ Payment Integration – Razorpay for secure transactions ✅ AWS S3 Storage – Scalable file storage for images ✅ Dashboard Analytics – Track sales, orders, and recent activity

Who is this for?

• Developers looking for a billing system backend
• Startups needing a scalable e-commerce solution
• Freelancers building custom billing applications

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✨ Tech Stack

Category	Technologies Used
Language	Java (Java 21)
Framework	Spring Boot (3.x)
Database	MySQL (JPA/Hibernate)
Authentication	JWT, Spring Security
Payments	Razorpay API
File Storage	AWS S3
Build Tool	Maven

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📦 Installation

Prerequisites

• Java 21 (or compatible)
• Maven 3.8+
• MySQL Database (or any supported RDBMS)
• AWS S3 Bucket (for file storage)
• Razorpay API Keys (for payment processing)

Quick Start

1. Clone the Repository

git clone https://github.com/Krishnendu/Billing_Software_Backend.git
cd Billing_Software_Backend

2. Set Up Environment Variables

Create a .env file (or use application.properties directly):

# Database Config
DB_URL=jdbc:mysql://localhost:3306/billing_db
DB_USERNAME=root
DB_PASSWORD=your_password

# AWS S3 Config
AWS_ACCESS_KEY=your_access_key
AWS_SECRET_KEY=your_secret_key
AWS_REGION=us-east-1
AWS_BUCKET_NAME=your-bucket-name

# JWT Config
JWT_SECRET_KEY=your_jwt_secret_key

# Razorpay Config
RZP_KEY_ID=your_razorpay_key_id
RZP_SECRET=your_razorpay_secret_key

# Server Port
PORT=8080

3. Run the Application

mvn spring-boot:run

The API will start at http://localhost:8080/api/v1.0

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🎯 Usage

1. Authentication (Login & JWT Token)

// Example: Login Request
POST /api/v1.0/login
{
    "email": "user@example.com",
    "password": "password123"
}

// Response: JWT Token
{
    "email": "user@example.com",
    "role": "ADMIN",
    "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."
}

2. Create a New Category (Admin Only)

// Example: Add Category with Image
POST /api/v1.0/admin/categories
Headers: Authorization: Bearer <JWT_TOKEN>
Body (multipart/form-data):
- category: {"name": "Electronics", "description": "Electronic devices"}
- file: <image-file.jpg>

3. Create an Order

// Example: Create Order
POST /api/v1.0/orders
Headers: Authorization: Bearer <JWT_TOKEN>
Body:
{
    "customerName": "John Doe",
    "phoneNumber": "1234567890",
    "cartItems": [
        {
            "itemId": "item-123",
            "name": "Laptop",
            "price": 999.99,
            "quantity": 1
        }
    ],
    "subTotal": 999.99,
    "tax": 50.00,
    "grandTotal": 1049.99,
    "paymentMethod": "CASH"
}

4. Process Payment with Razorpay

// Example: Create Razorpay Order
POST /api/v1.0/payments/create-order
Headers: Authorization: Bearer <JWT_TOKEN>
Body:
{
    "amount": 1049.99,
    "currency": "INR"
}

// Response: Razorpay Order ID
{
    "id": "order_1234567890",
    "amount": 104999,
    "currency": "INR",
    "status": "created"
}

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📁 Project Structure

src/
├── main/
│   ├── java/com/Krishnendu/BillingSoftware/
│   │   ├── config/          # Configuration classes
│   │   ├── controller/      # API Endpoints
│   │   ├── entity/          # Database Models
│   │   ├── filters/         # JWT Filter
│   │   ├── io/              # DTOs & Request/Response Objects
│   │   ├── repository/      # JPA Repositories
│   │   ├── service/         # Business Logic
│   │   └── utils/           # Helper Classes
│   └── resources/           # Config Files
│       ├── application.properties
│       └── static/           # Static Resources
└── test/                    # Unit & Integration Tests

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🔧 Configuration

Environment Variables

Variable	Description	Example Value
DB_URL	Database connection URL	jdbc:mysql://localhost:3306/db
AWS_ACCESS_KEY	AWS S3 Access Key	AKIAIOSFODNN7EXAMPLE
JWT_SECRET_KEY	JWT Secret Key	your_secure_jwt_key
RZP_KEY_ID	Razorpay API Key	rzp_test_key_id

Customization

• Modify application.properties for database, AWS, and JWT settings.
• Extend controllers to add new API endpoints.
• Adjust security rules in SecurityConfig.java.

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🤝 Contributing

We welcome contributions! Here’s how you can help:

1. Fork the Repository
2. Create a Feature Branch

   git checkout -b feature/your-feature

3. Commit Changes

   git commit -m "Add new payment method"

4. Push & Open a Pull Request

Development Setup

# Install dependencies
mvn clean install

# Run tests
mvn test

Code Style Guidelines

• Follow Java Best Practices (Lombok for boilerplate reduction).
• Use Spring Boot conventions for REST APIs.
• Write unit tests for critical logic.

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👥 Authors & Contributors

👤 Krishnendu – GitHub

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🐛 Issues & Support

• Report bugs via GitHub Issues.
• Need help? Open a discussion or contact me directly.

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🗺️ Roadmap

✅ Core Features – Complete (Authentication, CRUD, Payments) 🚧 Next Steps – Add WebSocket for real-time updates 🔜 Future Improvements – Multi-currency support, advanced analytics

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💡 Star & Follow for Updates!

🌟 Star this repo to support the project!

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"Build powerful billing systems with ease!" 🚀