# InsightSphere – Blog Application Backend 🚀

[![Java](https://img.shields.io/badge/Java-17-blue)](https://www.java.com/)
[![Spring Boot](https://img.shields.io/badge/Spring%20Boot-3.2-green)](https://spring.io/projects/spring-boot)
[![License](https://img.shields.io/badge/License-MIT-yellow)](LICENSE)

**InsightSphere** is a Java Spring Boot backend for a blog application, providing secure user registration and login with DTO mapping and password hashing. Ready to integrate with frontend applications and extend with JWT-based authentication.

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## Features

- **User Registration**
  - Unique username and email validation
  - Passwords hashed securely with Spring Security `PasswordEncoder`
  - Returns safe `UserDTO` (no passwords exposed)

- **User Login**
  - Authenticates username and password
  - Unified `InvalidCredentialsException` for security
  - Returns `UserDTO` with safe fields only

- **DTO Mapping**
  - All responses via `mapToDTO()` helper
  - Keeps sensitive data safe

- **Exception Handling**
  - `UserValidationException` for registration issues
  - `InvalidCredentialsException` for login failures

- **Extensible**
  - Placeholder methods for future features (update, delete, get users)
  - Ready for JWT, role-based access control, and blog post CRUD

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## Tech Stack

- Java 17+
- Spring Boot
- Spring Data JPA
- Spring Security (`PasswordEncoder`)
- Maven
- H2 / MySQL (or any SQL database)

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## Project Structure

com.insightsphere.blogapp │ ├─ controller # REST controllers (to be implemented) ├─ dto # Data Transfer Objects │ ├─ UserDTO.java │ └─ LoginDTO.java ├─ entity # JPA entities │ └─ User.java ├─ repository # Spring Data JPA repositories │ └─ UserRepository.java ├─ service │ ├─ UserService.java │ └─ impl │ └─ UserServiceImplementation.java └─ exception # Custom exceptions ├─ InvalidCredentialsException.java ├─ UserNotFoundException.java └─ UserValidationException.java

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## Getting Started

1. **Clone the repository**

```bash
git clone https://github.com/Sidhant2104/insightsphere.git
cd insightsphere

2. Configure Database

• Update application.properties with your DB details (H2/MySQL).

3. Build & Run

mvn clean install
mvn spring-boot:run

4. Test API

• Register: POST /api/users/register
• Login: POST /api/users/login

Register Payload

{
  "firstName": "John",
  "lastName": "Doe",
  "username": "johndoe",
  "email": "[email protected]",
  "password": "securePass123"
}

Login Payload

{
  "username": "johndoe",
  "password": "securePass123"
}

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Next Steps / Planned Features

• JWT authentication for stateless login
• Role-based access control
• Blog post CRUD operations
• Unit and integration tests
• Global exception handling with structured JSON responses

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Contributors

• Sidhant Singh (Leo) – Developer & Maintainer

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License

This project is open-source under the MIT License.