Pagination and sorting with Pageable in Spring Boot - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the output of this Pageable request?

Given a Spring Data repository method call with Pageable, what page content is returned?

Spring Boot

Pageable pageable = PageRequest.of(1, 3, Sort.by("name").ascending());
Page<User> page = userRepository.findAll(pageable);
List<User> users = page.getContent();
return users.stream().map(User::getName).toList();

A ["David", "Eve", "Frank"]

B ["Alice", "Bob", "Charlie"]

C ["Grace", "Heidi", "Ivan"]

D ["Jack", "Karl", "Liam"]

💡 Hint

Remember page index starts at 0, and sorting is ascending by name.

The Pageable requests page 1 (second page) with 3 items per page, sorted by name ascending. So the first page (index 0) has the first 3 names alphabetically, the second page has the next 3.

📝 Syntax

intermediate

Which Pageable creation code is correct for descending sort by age?

Choose the correct way to create a Pageable object that requests page 0, 5 items per page, sorted by age descending.

A Pageable pageable = PageRequest.of(0, 5, Sort.descending("age"));

B Pageable pageable = PageRequest.of(0, 5, Sort.by("age").descending());

C Pageable pageable = new Pageable(0, 5, Sort.by("age").desc());

D Pageable pageable = PageRequest.create(0, 5, Sort.by("age").descending());

💡 Hint

Check the official PageRequest factory method and Sort API.

PageRequest.of is the correct factory method. Sort.by("age").descending() creates the descending sort.

❓ state_output

advanced

What is the total number of pages for this Pageable query?

Assuming the database has 23 total items, what is the total number of pages returned by this Pageable query?

Spring Boot

Pageable pageable = PageRequest.of(0, 5);
Page<Item> page = itemRepository.findAll(pageable);
int totalPages = page.getTotalPages();

A 5

B 4

C 7

D 6

💡 Hint

Divide total items by page size and round up.

23 items with 5 per page means 4 pages fully filled (5*4=20) plus 1 page with 3 items, total 5 pages. 23/5 = 4.6, rounded up is 5 pages.

🔧 Debug

advanced

Why does this Pageable query throw an exception?

This code throws an IllegalArgumentException. What is the cause?

Spring Boot

Pageable pageable = PageRequest.of(-1, 10);
Page<Product> page = productRepository.findAll(pageable);

A Repository method findAll does not accept Pageable.

B Page size cannot be 10; must be less than 10.

C Page index cannot be negative; -1 is invalid.

D Sort parameter is missing, causing exception.

💡 Hint

Check the parameters for PageRequest.of.

PageRequest.of requires a non-negative page index. Negative page index causes IllegalArgumentException.

🧠 Conceptual

expert

How does Spring Data handle sorting when multiple Sort.Order objects are provided in Pageable?

If a Pageable is created with Sort.by(Order.asc("name"), Order.desc("age")), how will the sorting be applied?

A Sorts only by the last Order specified, ignoring the first.

B Sorts first by age descending, then by name ascending for items with the same age.

C Throws an exception because multiple Sort.Order objects are not allowed.

D Sorts first by name ascending, then by age descending for items with the same name.

💡 Hint

Think about how multi-level sorting works in databases.

Spring Data applies sorting in the order the Sort.Order objects are given. The first order is primary, the second is secondary.