🧾 POS Management System

Full Stack Application (React + Spring Boot + JWT)

A full-stack Point of Sale (POS) management system built with React (frontend) and Spring Boot (backend), secured using JWT authentication and following layered architecture principles.

---

🚀 Tech Stack

Frontend

• React JS
• React Router
• Axios
• Context API
• Protected Routes
• CSS / Bootstrap

Backend

• Spring Boot
• Spring Security
• JWT Authentication
• Spring Data JPA
• Hibernate
• MySQL
• Maven

---

🔐 Authentication & Security

This application uses JWT-based authentication.

• User login generates a JWT token
• Token is stored on the client side
• Token is attached to the Authorization header
• Spring Security validates every secured request
• Custom JWT filter handles authentication

Security Components:

• WebSecurityConfig
• AuthTokenFilter
• JwtUtils
• UserDetailsServiceImpl

---

🏗 Architecture

The backend follows a clean layered architecture:

Controller → Service → Repository → Database

Layers

• Controller Layer → Handles HTTP requests
• Service Layer → Contains business logic
• Repository Layer → Extends JpaRepository (DAO pattern)
• Entity Layer → Database mapping using JPA
• Security Layer → JWT configuration and filters

---

📂 Project Structure

Frontend (React)

React/
 ├── public/
 └── src/
     ├── Management/
     ├── utils/
     ├── App.js
     ├── Home.js
     └── LogIn.js

Backend (Spring Boot)

Springboot/pos/
 └── src/main/java/com/example/pos
     ├── Controller/
     ├── Dto/
     ├── entity/
     ├── repository/
     ├── Service/
     ├── Security/
     └── PosApplication.java

---

📌 Core Features

• JWT-based Authentication
• Secure REST APIs
• Item & Category Management
• Stock Management
• Purchase / Order Placement
• Receipt Handling
• Protected React Routes
• Clean Layered Architecture

---

🗄 Example Repository

@Repository
public interface UserRepository extends JpaRepository<User, Long> {
    Optional<User> findByUsername(String username);
}

• Automatically provides CRUD operations
• Custom method for authentication
• Used by Spring Security during login

---

▶️ Running the Application

Backend

cd Springboot/pos
mvn spring-boot:run

Runs on:

http://localhost:8080

Frontend

cd React
npm install
npm start

Runs on:

http://localhost:3000

---

📖 What This Project Demonstrates

• Full-stack application development
• Secure authentication using JWT
• REST API design
• Spring Security integration
• React state management with Context API
• Repository pattern with JPA
• Clean and maintainable architecture

---

👨‍💻 Author

Samiru Nuwanaka