Pagination and sorting with Pageable in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Pageable interface for pagination.

Spring Boot

import org.springframework.data.domain.[1];

Drag options to blanks, or click blank then click option'

APage

BPageable

CSort

DPageRequest

Attempts:

3 left

💡 Hint

Common Mistakes

Importing Page instead of Pageable

Importing Sort which is for sorting, not pagination

Importing PageRequest which is a class, not the interface

The Pageable interface is imported from org.springframework.data.domain to enable pagination.

2fill in blank

medium

Complete the method signature to accept pagination and sorting parameters using Pageable.

Spring Boot

public Page<User> getUsers([1] pageable) {

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APageRequest

BSort

CPageable

DPage

Attempts:

3 left

💡 Hint

Common Mistakes

Using PageRequest as parameter type instead of Pageable

Using Sort which only handles sorting

Using Page which is a return type, not parameter

The method parameter should be of type Pageable to receive pagination and sorting info.

3fill in blank

hard

Fix the error in the repository method to support pagination.

Spring Boot

Page<User> findAll([1] pageable);

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APageable

BSort

CList

DPageRequest

Attempts:

3 left

💡 Hint

Common Mistakes

Using PageRequest which is a class, not interface

Using Sort which is only for sorting

Using List which does not support pagination

The repository method must accept a Pageable parameter to enable pagination.

4fill in blank

hard

Fill both blanks to create a PageRequest with page number 0 and size 10 sorted by 'name' ascending.

Spring Boot

PageRequest [1] = PageRequest.[2](0, 10, Sort.by("name").ascending());

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ApageRequest

Bof

Ccreate

Dbuild

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'create' or 'build' instead of 'of' method

Using variable names that don't follow camelCase

The variable is named pageRequest and the static factory method to create it is of.

5fill in blank

hard

Fill all three blanks to return a paged and sorted list of users by calling repository with pageable.

Spring Boot

Page<User> users = userRepository.[1]([2]); return users.[3]();

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AfindAll

BpageRequest

CgetContent

DfindById

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'findById' which returns a single entity

Calling 'getContent' on repository instead of Page object

Passing wrong variable instead of pageable

The repository method to get paged data is findAll, passing the pageRequest variable, then calling getContent() to get the list of users.

Practice

1. What is the main purpose of using Pageable in Spring Boot?

easy

A. To fetch data in small chunks with optional sorting

B. To connect to the database directly

C. To write SQL queries manually

D. To handle user authentication

Solution

1. Step 1: Understand Pageable's role

   Pageable is used to request data in pages, not all at once.

2. Step 2: Recognize sorting feature

   It also supports sorting data by fields while fetching pages.

3. Final Answer:

   To fetch data in small chunks with optional sorting -> Option A

4. Quick Check:

   Pageable = Pagination + Sorting [OK]

Hint: Pageable means small pages + sorting [OK]

Common Mistakes:

• Thinking Pageable connects to database
• Confusing Pageable with authentication
• Assuming Pageable writes SQL queries

2. Which of the following is the correct way to create a Pageable object for page 2, size 5, sorted by "name" ascending?

easy

A. PageRequest.of(1, 5, Sort.by("name"))

B. PageRequest.of(2, 5, Sort.asc("name"))

C. PageRequest.of(2, 5, Sort.by("name"))

D. PageRequest.create(2, 5, Sort.by("name"))

Solution

1. Step 1: Understand zero-based page index

   Page numbers start at 0, so page 2 means index 1.

2. Step 2: Check method and sorting syntax

   Use PageRequest.of(page, size, Sort.by("field")) for ascending sort.

3. Final Answer:

   PageRequest.of(1, 5, Sort.by("name")) -> Option A

4. Quick Check:

   Page index zero-based + Sort.by correct [OK]

Hint: Page index starts at 0, so page 2 is index 1 [OK]

Common Mistakes:

• Using page number directly instead of zero-based index
• Using non-existent methods like Sort.asc
• Using PageRequest.create instead of PageRequest.of

3. Given this repository method call:
repository.findAll(PageRequest.of(0, 3, Sort.by("age")))
What will be the result?

medium

A. Error because Sort direction is missing

B. First 3 records sorted by age descending

C. All records without sorting

D. First 3 records sorted by age ascending

Solution

1. Step 1: Analyze PageRequest parameters

   Page 0 means first page, size 3 means 3 records, Sort.by("age") defaults to ascending.

2. Step 2: Understand repository behavior

   findAll with Pageable returns that page of sorted data.

3. Final Answer:

   First 3 records sorted by age ascending -> Option D

4. Quick Check:

   Page 0 + size 3 + ascending sort = first 3 sorted [OK]

Hint: Sort.by defaults to ascending if direction not set [OK]

Common Mistakes:

• Assuming descending sort without direction
• Thinking all records are returned
• Expecting error due to missing direction

4. What is wrong with this code snippet?

Pageable pageable = PageRequest.of(1, 10, Sort.asc("date"));

medium

A. Page index should start at 0, not 1

B. Sort.asc() method does not exist

C. Page size cannot be 10

D. PageRequest.of requires 4 parameters

Solution

1. Step 1: Check Sort method usage

   Spring Data uses Sort.by(), not Sort.asc().

2. Step 2: Verify other parameters

   Page index 1 and size 10 are valid; PageRequest.of takes 3 parameters here.

3. Final Answer:

   Sort.asc() method does not exist -> Option B

4. Quick Check:

   Use Sort.by() for sorting [OK]

Hint: Use Sort.by(), not Sort.asc() [OK]

Common Mistakes:

• Using Sort.asc() or Sort.desc() which don't exist
• Thinking page index must be 0 always
• Believing PageRequest.of needs 4 parameters

5. You want to fetch the third page of size 4, sorted by "price" descending and then by "name" ascending. Which Pageable creation is correct?

hard

A. PageRequest.of(2, 4, Sort.by("price", "name"))

B. PageRequest.of(3, 4, Sort.by("price").descending().and(Sort.by("name")))

C. PageRequest.of(2, 4, Sort.by(Sort.Order.desc("price"), Sort.Order.asc("name")))

D. PageRequest.of(2, 4, Sort.by("price").desc().and(Sort.by("name").asc()))

Solution

1. Step 1: Identify zero-based page index

   Third page means index 2 (0,1,2).

2. Step 2: Create Sort with multiple orders

   Use Sort.by(Order.desc("price"), Order.asc("name")) to combine sorting directions.

3. Step 3: Check syntax correctness

   PageRequest.of(2, 4, Sort.by(Sort.Order.desc("price"), Sort.Order.asc("name"))) uses correct PageRequest.of and Sort.by with orders.

4. Final Answer:

   PageRequest.of(2, 4, Sort.by(Sort.Order.desc("price"), Sort.Order.asc("name"))) -> Option C

5. Quick Check:

   Page 2 + size 4 + multi-sort orders correct [OK]

Hint: Use Sort.Order for multi-direction sorting [OK]

Common Mistakes:

• Using page number 3 instead of index 2
• Trying to chain .desc() or .asc() methods that don't exist
• Passing multiple fields without specifying order