Verify the queries executed by spring jpa repository

Question

We've got a spring repository, and due to a change of behaviour, our lazy loading stopped working. We noticed that multiple queries were being executed to load the related objects.

We've fixed the issue, but I'd like to write a test to tell us what queries we're running, or at least check we're not querying specific tables.

I've had a look around, and I can't find any examples. I thought the TestEntityManager might help, but there's no validation methods on that class.

Has anyone got any pointers, or written a test which validates similar behaviour?

Answer 1

I found a pretty elegant solution to this using hibernate statistics:

//Enable hibernate statistics
@DataJpaTest(properties = "spring.jpa.properties.hibernate.generate_statistics=true")
public class MyRepositoryIT {

    @Autowired
    private MyRepository repository;

    @Autowired
    private EntityManager entityManager;

    @Test
    @Transactional
    @Sql
    void shouldNotQueryLazilyRelatedEntities() {
        //Query repository and check result is not null
        MyEntity response = repository.findById(1L);
        assertThat(response).isNotNull();

        //Load statistics from entity manager session
        Session session = entityManager.unwrap(Session.class);
        Statistics statistics = session.getSessionFactory().getStatistics();

        //Assert that only the expected entity is loaded, and not the lazy relationships.
        assertThat(statistics.getEntityLoadCount()).isEqualTo(1);
        assertThat(statistics.getEntityStatistics(MyEntity.class.getName()).getLoadCount()).isEqualTo(1);
        assertThat(statistics.getEntityStatistics(LazyRelation.class.getName()).getLoadCount()).isEqualTo(0);
    }

}