Pagination and sorting with Pageable in Spring Boot - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the Pageable interface in Spring Boot?

The Pageable interface helps to request a specific page of data with a defined size and sorting order. It makes it easy to handle pagination and sorting in database queries.

beginner

How do you specify sorting when using Pageable?

You can specify sorting by using PageRequest.of(page, size, Sort.by("fieldName").ascending()) or PageRequest.of(page, size, Sort.by("fieldName").descending()) to sort the results by a field in ascending or descending order.

intermediate

What does the Page object returned by a repository method contain?

The Page object contains the list of items for the requested page, total number of pages, total number of elements, current page number, and page size. It helps to navigate through paged data easily.

beginner

How can you enable pagination and sorting in a Spring Data JPA repository method?

Add a Pageable parameter to the repository method signature, for example: Page<Entity> findAll(Pageable pageable);. Spring Data will automatically apply pagination and sorting based on the Pageable argument.

advanced

What is the difference between Pageable and Slice in Spring Data?

Pageable returns a Page which contains total count information, while Slice only knows if there is a next slice available and does not fetch total count, which can improve performance when total count is not needed.

Which method creates a Pageable object for page 2 with 10 items per page sorted by 'name' ascending?

A PageRequest.of(0, 10, Sort.by("name").ascending())

B PageRequest.of(2, 10, Sort.by("name").ascending())

C PageRequest.of(1, 10, Sort.by("name").ascending())

D PageRequest.of(1, 10, Sort.by("name").descending())

Page numbers are zero-based, so page 2 means index 1. The correct call is PageRequest.of(1, 10, Sort.by("name").ascending()).

What does the Page interface provide besides the list of items?

A Only the list of items

B Sorting configuration only

C Database connection info

D Total pages, total elements, current page number, page size

Page provides metadata like total pages, total elements, current page number, and page size along with the content.

How do you add pagination support to a Spring Data JPA repository method?

A Add a <code>Pageable</code> parameter to the method

B Add a <code>Sort</code> parameter only

C Use <code>List</code> return type

D No changes needed

Adding a Pageable parameter enables pagination and sorting automatically.

Which of the following is true about Slice compared to Page?

A <code>Slice</code> does not contain total count information

B <code>Slice</code> contains total pages info

C <code>Slice</code> fetches all data at once

D <code>Slice</code> is deprecated

Slice only knows if there is a next slice and does not fetch total count, improving performance.

What is the default sort direction if not specified in Pageable?

A Ascending

B No sorting applied

C Random

D Descending

If no Sort is provided when creating the Pageable, no sorting is applied.

Explain how to implement pagination and sorting in a Spring Boot REST API using Pageable.

Think about how to request a specific page and sort order, and how to return the data with helpful info.

Describe the difference between Page and Slice in Spring Data pagination.

Focus on what metadata each provides and when you might prefer one over the other.