📚 Library API - Spring Boot

REST API built with Spring Boot, following industry best practices for security, testing, and scalability.
The system simulates a library catalog, where users can browse books and administrators manage the catalog (create, update, and delete books).

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🚀 Technologies

• Java
• Spring Boot
• Spring Security
• JWT (JSON Web Token)
• Spring Data JPA
• Hibernate
• MySQL
• Maven
• Docker & Docker Compose
• Prometheus
• Grafana
• Springdoc OpenAPI (Swagger)
• JUnit

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🔧 Features

• ✅ Full CRUD operations for books (admin only)
• ✅ Public access for users to view books
• ✅ Pagination and sorting
• ✅ Filtering via query parameters (one filter at a time)
• ✅ Authentication with JWT
• ✅ Role-based access control (USER / ADMIN)
• ✅ Data validation with Bean Validation
• ✅ DTO pattern for request/response
• ✅ Global exception handling
• ✅ Unit tests (Controller, Service, Repository, JWT Service)
• ✅ Integration tests (including JWT and security)
• ✅ API documentation (Swagger/OpenAPI)
• ✅ Monitoring with Prometheus
• ✅ Metrics visualization with Grafana
• ✅ Dockerized environment

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🧩 Architecture

The application follows a layered architecture, ensuring clear separation of concerns:

Controller → Service → Repository → Database
      ↓
     DTO
      ↓
 Security (JWT)
      ↓
Exception Handler
      ↓
 Actuator → Prometheus → Grafana

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📁 Project Structure

src/
├── main/
│   ├── java/library/com/
│   │   ├── configurations/
│   │   ├── controller/
│   │   ├── dto/
│   │   ├── entity/
│   │   ├── exceptions/
│   │   ├── repository/
│   │   ├── service/
│   │   └── ComApplication.java
│   └── resources/
│       └── application.properties
│
├── test/
│   ├── java/library/com/
│   │   ├── configurations/
│   │   ├── controller/
│   │   ├── integration/
│   │   ├── repository/
│   │   ├── service/
│   │   └── util/
│   └── resources/
│       └── application-test.properties

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🔐 Authentication & Authorization

• Stateless authentication using JWT
• User registration and login
• Protected routes with Spring Security

Roles:

• USER → can view books
• ADMIN → can create, update, and delete books

Example:

Authorization: Bearer YOUR_TOKEN

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📄 Pagination & Filtering

Example:

GET /books?page=0&size=10&sort=title,asc

Available filters (single use only):

• title → partial, case-insensitive search
• author → filter by author (case-insensitive)
• genre → filter by genre

⚠️ Only one filter can be applied per request.

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⚠️ Validation & Business Rules

• Required fields (e.g., title, author, description, status)
• Publication date cannot be in the future
• ID is automatically generated by the database
• Text search is partial and case insensitive

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🧪 Testing

The project includes comprehensive test coverage:

Unit tests

• Controller
• Service
• Repository
• JWT Service

Integration tests

• Full application flow
• JWT authentication
• Security validation

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📊 Monitoring

Metrics endpoint:

/actuator/prometheus

• Prometheus collects application metrics
• Grafana provides visualization dashboards

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📚 API Documentation

Documentation is automatically generated using Springdoc OpenAPI.

Access:

http://localhost:8080/swagger-ui/index.html

Features:

• Interactive endpoint testing
• Request/response visualization
• Clear API contract

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🐳 Docker

Run the full environment using Docker:

mvn clean package
docker compose up --build

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▶️ How to Run

1. Clone the repository

git clone https://github.com/JKSJ15/libraryAPI.git

2. Navigate to the project

cd libraryAPI

3. Configure the database

Edit application.properties

4. Run the application

./mvnw spring-boot:run

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💡 About the Project

This project was built to simulate a real-world library system, where users can explore a book catalog and administrators manage the collection.

It focuses on applying professional back-end concepts such as:

• Security with JWT
• Layered architecture
• Testing strategies
• Monitoring and observability

Using Java and Spring Boot.