Mark
#1
This guide shows how to use H2 database for running integration tests in Spring Boot, ensuring fast and isolated test runs.

1. Add Dependencies

In pom.xml: 
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
  <groupId>com.h2database</groupId>
  <artifactId>h2</artifactId>
  <scope>test</scope>
</dependency>
Using <scope>test</scope> ensures H2 is only used for tests.

2. Configure H2

In src/test/resources/application-test.properties: 
spring.datasource.url=jdbc:h2:mem:testdb;DB_CLOSE_DELAY=-1
spring.datasource.driver-class-name=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=
spring.jpa.hibernate.ddl-auto=create-drop

3. Example Entity

@Entity
public class User {
  @Id @GeneratedValue
  private Long id;
  private String name;
}

4. Repository

public interface UserRepository extends JpaRepository<User, Long> {}

5. Write Integration Test

@SpringBootTest
@TestPropertySource(locations = "classpath:application-test.properties")
class UserRepositoryIT {

  @Autowired private UserRepository repo;

  @Test
  void testSaveAndFind() {
    User u = new User();
    u.setName("Alice");
    repo.save(u);

    assertEquals(1, repo.findAll().size());
  }
}

6. Run Tests

Execute: 
mvn test
The app starts with H2 in-memory DB, runs integration tests, and cleans up after.

image quote pre code
Share: