@DataJpaTest Spring Boot Example

In this tutorial, we will learn how to use Spring boot provided @DataJpaTest annotation to test Repository layer components.

We use Spring boot starter test dependency to write JUnit tests for Repository layer components:

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        

@DataJpaTest Annotation Overview

Spring Boot provides the @DataJpaTest annotation to test the persistence layer components that will autoconfigure in-memory embedded database for testing purposes.

The @DataJpaTest annotation doesn’t load other Spring beans (@Components, @Controller, @Service, and annotated beans) into ApplicationContext. By default, it scans for @Entity classes and configures Spring Data JPA repositories annotated with @Repository annotation.

By default, tests annotated with @DataJpaTest are transactional and roll back at the end of each test.

Spring boot provided @DataJpaTest annotation is not only to test Spring Data JPA repositories but it also supports to test JPA-related components.

For example:

@DataJpaTest Spring Boot Example

Create Spring Boot Application

Using spring initialize, create a Spring Boot project and add the following dependencies:

• Spring Data JPA
• Lombok
• H2 Driver

Generate the Spring boot project as a zip file, extract it, and import it into IntelliJ IDEA.

Make sure that you have the below dependencies added to your pom.xml file:

            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-data-jpa</artifactId>
            </dependency>
            
            <dependency>
                <groupId>com.h2database</groupId>
                <artifactId>h2</artifactId>
                <scope>runtime</scope>
            </dependency>
            
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <optional>true</optional>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
            

Create JPA Entity

Next, let's create a Student JPA entity:

package net.javaguides.spirngboot.entity;

    import lombok.*;
    
    import jakarta.persistence.*;
    
    @Setter
    @Getter
    @Builder
    @AllArgsConstructor
    @NoArgsConstructor
    @Entity
    @Table(name = "students")
    public class Student {
    
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private long id;
    
        @Column(name = "first_name")
        private String firstName;
    
        @Column(name = "last_name")
        private String lastName;
        private String email;
    }

Create Spring Data JPA Repository

Let's create StudentRepository which extends the JpaRepository interface:

package net.javaguides.spirngboot.repository;

    import net.javaguides.spirngboot.entity.Student;
    import org.springframework.data.jpa.repository.JpaRepository;
    
    public interface StudentRepository extends JpaRepository<Student, Long> {
    }

JUnit Tests for Data Access or Repository Layer with H2 database

Let's create StudentRepositoryTests class and add the following content to it:

package net.javaguides.spirngboot.repository;

    import net.javaguides.spirngboot.AbstractContainerBaseTest;
    import net.javaguides.spirngboot.entity.Student;
    import org.junit.jupiter.api.Assertions;
    import org.junit.jupiter.api.Test;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
    
    import static org.junit.jupiter.api.Assertions.*;
    
    @DataJpaTest
    class StudentRepositoryTest {
    
        @Autowired
        private StudentRepository studentRepository;
    
        // JUnit for save student operation - BDD style
        @Test
        public void givenStudentObject_whenSave_thenReturnSavedStudent(){
    
            // given - setup or precondition
            Student student = Student.builder().firstName("Ramesh")
                    .lastName("fadatare").email("ramesh@gmail.com").build();
    
            // when - action or the testing
            Student savedStudent = studentRepository.save(student);
    
            // then - very output
            Assertions.assertNotNull(savedStudent);
            Assertions.assertNotNull(savedStudent.getId());
    
        }
    
        // JUnit for findById student operation - BDD style
        @Test
        public void givenStudentId_whenfindbyId_thenReturnSavedStudent(){
    
            // given - setup or precondition
            Student student = Student.builder().firstName("Ramesh")
                    .lastName("fadatare").email("ramesh@gmail.com").build();
            Student savedStudent = studentRepository.save(student);
    
            // when - action or the testing
            Student studentDB = studentRepository.findById(student.getId()).get();
    
            // then - very output
            Assertions.assertNotNull(studentDB);
        }
    }

Spring Boot provides the @DataJpaTest annotation to test the persistence layer components that will autoconfigure in-memory embedded database for testing purposes. In this example, we are using an H2 in-memory database for testing purposes.

Run JUnit tests

Conclusion

In this tutorial, we have learned how to use Spring boot provided @DataJpaTest annotation to test Repository layer components.