🛡️ Simple Auth Backend (Spring Boot + MySQL + JWT)

This is a simple backend application built with Spring Boot that supports user registration and login, with password hashing and JWT-based authentication.

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🚀 Features

• ✅ User Registration (Full Name, Email, Password)
• 🔐 Secure Login with JWT Token Generation
• 🔒 Password Hashing with BCrypt
• 🔁 Stateless Authentication using JWT
• ❌ Error Handling & Input Validation
• ✅ Protected Endpoints that require valid JWT

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🧰 Tech Stack

Layer	Technology
Language	Java
Framework	Spring Boot
Security	Spring Security + JWT
Password Hash	BCrypt
Database	MySQL
Testing Tool	Postman
Build Tool	Maven

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🏗️ Project Structure

/authdemo ├── controller │ └── AuthController.java ├── config │ ├── SecurityConfig.java │ └── JwtAuthenticationFilter.java ├── entity │ └── User.java ├── repository │ └── UserRepository.java ├── service │ ├── AuthService.java │ └── JwtUtil.java ├── dto │ ├── LoginRequest.java │ └── RegisterRequest.java ├── AuthDemoApplication.java └── README.md ✅

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🧪 How to Test

1️⃣ Register a User

Endpoint: POST /api/auth/register
Body:

{
  "fullName": "kaithamalai",
  "email": "kaithamalai@example.com",
  "password": "zxcvbhnjm123"
}

2️⃣ Login
Endpoint: POST /api/auth/login
Body:
json
{
  "email": "kaithamalai@example.com",
  "password": "zxcvbhnjm123"
}

Response:
Returns a JWT token if login is successful:
{
  "token": "eyJhbGciOiJIUzI1NiJ9..."
}

3️⃣ Access a Protected Endpoint
Endpoint: GET /api/user/me
Headers:
Authorization: Bearer <paste-your-token-here>
Response:
"Hello, kaithamalai@example.com! This is a protected endpoint."

🛠️ Setup Instructions
Clone the repo

git clone https://github.com/your-username/auth-backend.git
cd auth-backend

Configure application.properties

spring.datasource.url=jdbc:mysql://localhost:3306/your_db
spring.datasource.username=your_db_user
spring.datasource.password=your_db_pass

Run the app using IntelliJ or:

mvn spring-boot:run
Use Postman to test endpoints.


🧑‍💻 Author
Name: Kaithamalai.M
Email: kaithamalairbr@gmail.com