How do you handle pagination in REST APIs with Spring Boot?

Table of Contents

• Introduction
• Handling Pagination in Spring Boot REST APIs
  • 1. Using the **Pageable** Interface
    • Example: Paginated API Endpoint with Pageable
    • Example Request:
  • 2. Handling Pagination with Spring Data Repositories
    • Example: Repository Method for Paginated Results
  • 3. Return Paginated Results in the API Response
    • Example: Returning Paginated Results with Metadata
  • 4. Handling Sorting with Pagination
    • Example: Sorting with Pagination
    • Example Request:
• Practical Example: Paginated and Sorted API Response
  • • Example Response:
• Conclusion

Introduction

Pagination is a common requirement in REST APIs, especially when dealing with large datasets. Spring Boot provides robust support for pagination through Spring Data's Pageable interface and the Page class. Pagination allows APIs to return manageable chunks of data instead of overwhelming clients with large datasets in a single response. This guide explores how to implement pagination in Spring Boot REST APIs, enabling efficient data retrieval and improved performance.

Handling Pagination in Spring Boot REST APIs

1. Using the **Pageable** Interface

The Pageable interface in Spring Data represents pagination information, such as the page number, page size, and sorting criteria. It is typically passed as a method parameter in a controller method to handle paginated requests.

Example: Paginated API Endpoint with Pageable

In this example:

• The page and size parameters are extracted from the request.
• A Pageable object is created using PageRequest.of(page, size) to specify the page number and size.
• The paginated results are returned from the productService.findPaginated(pageable) method.

Example Request:

This request fetches the second page of products, with a maximum of 5 products per page.

2. Handling Pagination with Spring Data Repositories

Spring Data JPA repositories provide built-in methods to handle pagination. The PagingAndSortingRepository interface extends CrudRepository and includes methods like findAll(Pageable pageable), which returns a Page object.

Example: Repository Method for Paginated Results

In this example, the findAll(Pageable pageable) method is used to fetch paginated results from the database.

3. Return Paginated Results in the API Response

The Page class in Spring Data represents a page of results, including metadata like the total number of pages, total elements, and whether there are more pages. You can return this information in your REST API response.

Example: Returning Paginated Results with Metadata

In this example, the Page<Product> object returned by the repository or service includes:

• The content of the current page (the list of products).
• The total number of elements.
• The total number of pages.
• The current page number and size.

4. Handling Sorting with Pagination

You can also add sorting to your paginated results using the Sort class in combination with the Pageable interface. Sorting can be done by specifying the sort properties in the request.

Example: Sorting with Pagination

Example Request:

This request fetches the second page of products, sorted by price in ascending order.

Practical Example: Paginated and Sorted API Response

Example Response:

In this example:

• The content array contains the paginated results.
• The pageable object includes information about the current page, page size, and sorting.
• The totalPages and totalElements fields show the total number of pages and elements available.

Conclusion

Pagination in Spring Boot REST APIs can be efficiently implemented using Spring Data’s Pageable interface and the Page class. By extracting pagination parameters from the request, you can return manageable chunks of data to clients. This improves performance and user experience, especially when dealing with large datasets. Adding sorting functionality further enhances flexibility, enabling clients to retrieve data in an ordered manner.