📚 Library API – Spring Boot & Spring Data JPA

👋 About the Project Library API is a backend application built with Spring Boot to demonstrate real-world data access patterns using Spring Data JPA. This project was developed as part of a Udemy course, with a strong focus on persistence layer design, repository abstractions, and database interaction best practices commonly used in professional Java applications.

💼 Why This Project Matters This project showcases practical skills that are highly relevant for Java backend roles, including: Clean separation of domain, repository, and service layers Effective use of Spring Data JPA Writing maintainable and testable data access code Implementing custom queries and search logic Applying best practices for relational database persistence

🛠️ Tech Stack Java 17 Spring Boot Spring Data JPA Hibernate PostgreSQL Maven JUnit 5 Mockito Docker

🧩 Key Features CRUD operations for library resources Repository interfaces using derived query methods Custom JPQL queries Pagination and filtering support Integration with PostgreSQL Repository-level automated tests

🧱 Architecture Overview The application follows a layered architecture: Controller → Service → Repository → Database Domain Layer: JPA entities representing business models Repository Layer: Spring Data JPA repositories Service Layer: Business rules and orchestration Test Layer: Focused repository tests ensuring query correctness

🧪 Testing Strategy Repository tests using @DataJpaTest Validation of custom queries and search behavior Isolated database testing Emphasis on reliability of the persistence layer

🗄️ Database Setup The project uses PostgreSQL. Helpful resources included in the repository: comandos-sql.txt – SQL scripts for schema and data setup comandos-docker.txt – Docker commands for running PostgreSQL locally

🚀 Getting Started Prerequisites Java 17+ Docker (recommended) Maven Running the Application git clone https://github.com/your-username/libraryapi.git cd libraryapi ./mvnw spring-boot:run

📌 What I Practiced in This Project Designing repositories with Spring Data JPA Creating efficient database queries Testing persistence logic Working with PostgreSQL in a Dockerized environment Applying backend development best practices

📄 License This project is licensed under the MIT License.