Exploring the Scroll API in Spring Data JPA with Spring Boot 3.1

Scroll API in spring boot 3.1

In the world of Spring Boot 3.1, Spring Data JPA continues to empower developers with efficient and streamlined ways to interact with databases. One powerful feature introduced in this version is the Scroll API. In this brief blog post, we’ll take a quick dive into what the Scroll API is, why it’s useful, and how you can leverage it in your Spring Boot 3.1 applications.

What is the Scroll API?

The Scroll API is a valuable addition to Spring Data JPA that addresses the need for processing large data sets without loading everything into memory. It enables efficient traversal of database records in a streaming-like fashion, preventing memory exhaustion when dealing with substantial result sets.

Why is the Scroll API Useful?

Consider scenarios where your application needs to handle a considerable number of records from a database. Fetching all these records into memory at once can lead to performance bottlenecks and increased memory usage. The Scroll API provides a solution by allowing you to stream records one by one, effectively circumventing these issues.

How to Use the Scroll API in Spring Boot 3.1

Let’s walk through a basic example of using the Scroll API in a Spring Boot 3.1 application.

Dependency Setup:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

Repository Setup:

import org.springframework.data.jpa.repository.JpaRepository;

public interface BookRepository extends JpaRepository<Book, Long> {
    // Custom query methods (if needed)
}

Using Scroll API:

public List<BookReview> getBooksUsingOffset(String rating) {
    OffsetScrollPosition offset = ScrollPosition.offset();

    Window<BookReview> bookReviews = bookRepository.findFirst5ByBookRating(rating, offset);
    List<BookReview> bookReviewsResult = new ArrayList<>();
    do {
        bookReviews.forEach(bookReviewsResult::add);
        bookReviews = bookRepository.findFirst5ByBookRating(rating, (OffsetScrollPosition) bookReviews.positionAt(bookReviews.size() - 1));
    } while (!bookReviews.isEmpty() && bookReviews.hasNext());

    return bookReviewsResult;
}

Scrolling Using Keyset-Filtering:

public List<BookReview> getBooksUsingKeySetFiltering(String rating) {
    WindowIterator<BookReview> bookReviews = WindowIterator.of(position -> bookRepository
      .findFirst5ByBookRating(rating, (KeysetScrollPosition) position))
      .startingAt(ScrollPosition.keyset());
    List<BookReview> bookReviewsResult = new ArrayList<>();
    bookReviews.forEachRemaining(bookReviewsResult::add);

    return bookReviewsResult;
}

Keyset filtering helps the retrieval of a subset of results using the built-in capabilities of the database aiming to reduce the computation and IO requirements for individual queries.

Conclusion

Spring Data JPA’s Scroll API in Spring Boot 3.1 is a powerful tool to handle large data sets efficiently. By using a streaming approach to retrieve and process database records, you can avoid memory overhead and achieve better application performance. Integrating the Scroll API into your Spring Boot projects is a step toward building robust and scalable data-driven applications

Thank you for reading until the end. Please consider following the writer and this publication. Visit Stackademic to find out more about how we are democratizing free programming education around the world.