📚 Library Management API

A production‑grade REST API built with Spring Boot 3 that enables comprehensive library management with secure authentication and role-based permissions.

✨ Features

• JWT Authentication – Users can register, log in, and receive a secure token

• Role‑Based Access – ADMIN can manage books and categories; USER can view and review books

• Book Management – Full CRUD for books (title, author, ISBN, publication year, category)

• Reviews – Users can post, update, and delete their own reviews; admins can delete any review

• Categories – Books are organised into categories (Fiction, Non‑Fiction, Science, History, Fantasy)

• Pagination & Sorting – List endpoints support page, size, and sort parameters

• Global Exception Handling – Consistent JSON error responses with validation details

🛠️ Tech Stack

Java 21, Spring Boot 3.5.16, Spring Security 6, JJWT, PostgreSQL, Spring Data JPA, Hibernate, Maven, Lombok, Jakarta Bean Validation

📡 API Endpoints

Authentication: POST /api/auth/register, POST /api/auth/login

Books: GET /api/books, GET /api/books/{id}, POST /api/books, PUT /api/books/{id}, DELETE /api/books/{id}

Reviews: POST /api/reviews, GET /api/reviews/book/{bookId}, GET /api/reviews/my-reviews, PUT /api/reviews/{reviewId}, DELETE /api/reviews/{reviewId}

📁 Project Structure

Clean layered architecture with separation of concerns: controller, service, repository, entity, DTO, security, config, and exception packages.

📚 What I Learned

• Securing REST APIs with Spring Security and JWT

• Working with JPA relationships (@ManyToMany, @OneToMany, @ManyToOne)

• Implementing role‑based access control with @PreAuthorize

• PostgreSQL integration in Spring Boot

• Adding pagination and sorting with Spring Data Pageable

• Creating a global exception handler for standardised error responses