Spring Data JPA Sorting Overview

To use paging and sorting APIs provided by Spring Data JPA, your repository interface must extend the PagingAndSortingRepository interface.

For sorting, we are going to use the below method from the PagingAndSortingRepository interface:

    Iterable < T > findAll(Sort sort);

Note: Spring Data JPA has SimpleJPARepository class which implements PagingAndSortingRepository interface methods so we don't have to write a code to implement PagingAndSortingRepository interface methods.

Let's create a Spring boot project from the scratch and let's implement sorting with multiple fields using Spring Data JPA.

1. Creating Spring Boot Project

Spring Boot provides a web tool called https://start.spring.io to bootstrap an application quickly. Just go to https://start.spring.io and generate a new spring boot project.
Use the below details in the Spring boot creation:
Project Name: spring-data-jpa-course
Project Type: Maven
Choose dependencies: Spring Data JPA, MySQL Driver, Lombok
Package name: net.javaguides.springboot

2. Maven Dependencies

Here is the complete pom.xml for your reference:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>3.0.4</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>net.javaguides</groupId>
	<artifactId>spring-data-jpa-course</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>spring-data-jpa-course</name>
	<description>Demo project for Spring Boot</description>
	<properties>
		<java.version>17</java.version>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-data-jpa</artifactId>
		</dependency>

		<dependency>
			<groupId>com.mysql</groupId>
			<artifactId>mysql-connector-j</artifactId>
			<scope>runtime</scope>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

3. Configure MySQL database

Let's use the MySQL database to store and retrieve the data in this example and we gonna use Hibernate properties to create and drop tables.

Open the application.properties file and add the following configuration to it:

spring.datasource.url=jdbc:mysql://localhost:3306/demo?useSSL=false
spring.datasource.username=root
spring.datasource.password=Mysql@123

spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQLDialect

spring.jpa.hibernate.ddl-auto = create-drop

Make sure that you will create a demo database before running the Spring boot application.

Also, change the MySQL username and password as per your MySQL installation on your machine.

4. Create JPA Entity - Product.java

Let's create an entity package inside a base package "net.javaguides.springboot".

Within the entity package, create a Product class with the following content:

import lombok.*;
import org.hibernate.annotations.CreationTimestamp;
import org.hibernate.annotations.UpdateTimestamp;

import jakarta.persistence.*;
import java.math.BigDecimal;
import java.time.LocalDateTime;

@Entity
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@ToString
@Table(
        name = "products",
        schema = "ecommerce",
        uniqueConstraints = {
                @UniqueConstraint(
                        name = "sku_unique",
                        columnNames = "stock_keeping_unit"
                )
        }
)
public class Product {

    @Id
    @GeneratedValue(
            strategy = GenerationType.SEQUENCE,
            generator = "product_generator"
    )

    @SequenceGenerator(
            name = "product_generator",
            sequenceName = "product_sequence_name",
            allocationSize = 1
    )
    private Long id;

    @Column(name = "stock_keeping_unit", nullable = false)
    private String sku;

    @Column(nullable = false)
    private String name;

    private String description;
    private BigDecimal price;
    private boolean active;
    private String imageUrl;

    @CreationTimestamp
    private LocalDateTime dateCreated;

    @UpdateTimestamp
    private LocalDateTime lastUpdated;
}

Note that we are using Lombok annotations to reduce the boilerplate code.

5. Create Spring Data JPA Repository

The next thing we’re gonna do is to create a repository to access Product entity data from the database.

The JpaRepository interface defines methods for all the CRUD operations on the entity, and a default implementation of the JpaRepository called SimpleJpaRepository.

Let's create a repository package inside a base package "net.javaguides.springdatarest".

Within the repository package, create a ProductRepository interface with the following content:

import com.springdatajpa.springboot.entity.Product;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.repository.query.Param;

import java.math.BigDecimal;


public interface ProductRepository extends JpaRepository<Product, Long> 
{

}

6. Spring Data JPA Sorting with Multiple Fields Implementation

Let's write the JUnit test and within the JUnit test, we will write a logic to implement sorting using Spring Data JPA:

import com.springdatajpa.springboot.entity.Product;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.domain.Sort;

import java.util.List;

@SpringBootTest
public class PaginationAndSortingTest {

    @Autowired
    private ProductRepository productRepository;

    @Test
    void sortingByMultipleFields(){
        String sortBy = "name";
        String sortByDesc = "description";
        String sortDir = "desc";

        Sort sortByName = sortDir.equalsIgnoreCase(Sort.Direction.ASC.name())?
                Sort.by(sortBy).ascending(): Sort.by(sortBy).descending();

        Sort sortByDescription = sortDir.equalsIgnoreCase(Sort.Direction.ASC.name())?
                Sort.by(sortByDesc).ascending(): Sort.by(sortByDesc).descending();

        Sort groupBySort = sortByName.and(sortByDescription);

        List<Product> products = productRepository.findAll(groupBySort);

        products.forEach((p) ->{
            System.out.println(p);
        });
    }
}

If we wish to apply to sort on multiple columns or group by sort, then that is also possible by creating Sort using simple builder pattern steps:

        String sortBy = "name";
        String sortByDesc = "description";
        String sortDir = "desc";

        Sort sortByName = sortDir.equalsIgnoreCase(Sort.Direction.ASC.name())?
                Sort.by(sortBy).ascending(): Sort.by(sortBy).descending();

        Sort sortByDescription = sortDir.equalsIgnoreCase(Sort.Direction.ASC.name())?
                Sort.by(sortByDesc).ascending(): Sort.by(sortByDesc).descending();

        Sort groupBySort = sortByName.and(sortByDescription);

Output:

Once you run the JUnit test, you will get the below output:

Note that Spring Data JPA behind scenes uses Hibernate to generate the below SQL query for sorting:

    select
        product0_.id as id1_0_,
        product0_.active as active2_0_,
        product0_.date_created as date_cre3_0_,
        product0_.description as descript4_0_,
        product0_.image_url as image_ur5_0_,
        product0_.last_updated as last_upd6_0_,
        product0_.name as name7_0_,
        product0_.price as price8_0_,
        product0_.stock_keeping_unit as stock_ke9_0_ 
    from
        products product0_ 
    order by
        product0_.name desc,
        product0_.description desc