Paginação Simples e Eficiente com Spring Data 🧙‍♂️

This text explains how to implement pagination in a Spring Boot REST API using characters from Lord of the Rings as an example. Pagination is crucial for handling endpoints that return large datasets, preventing performance issues and improving user experience. The process involves creating a JPA entity (Personagem), a repository extending JpaRepository, and a DTO (PersonagemResponseDTO) for data transfer. DTOs are essential for security, decoupling, performance, and API versioning. The implementation requires modifications in the Service layer, using `Pageable` and `findAll(pageable)`, and in the Controller, utilizing `@PageableDefault` to define default pagination parameters. Practical usage involves constructing requests with parameters like `page`, `size`, and `sort`. Testing can be done manually with tools like Postman or through unit tests using MockMvc, with considerations for data loading and SQL verification. The text emphasizes the importance of constructor injection over field injection (`@Autowired`) for immutability, testability, and explicit dependency management. Finally, it offers tips like setting reasonable limits, using database indexes, and considering the return of metadata.