Question

I’m working with many classes which are annotated with javax.persistence.Entity and the like. My project is about generating metadata about JPA-annotated classes rather than persistence by itself, so I’m using them as test cases.

Rather than firing up Hibernate or some other JPA provider, I’d like to programatically check – part of my unit tests – that my JPA declarations are indeed valid.

What’s the easiest way of doing that?

Answer 1

Just create the simplest possible SessionFactory or whatever EclipseLink or OpenJPA provide behind the EntityManagerFactory and let them validate it (using some dummy in-memory database, if needed). It’s too complex to reinvent it.

For Hibernate this can be done using Configuration.buildMappings:

@RunWith(Theories.class)
public class EntitiesAreValidTest {

    @DataPoints
    public static Class<?>[] entities = new Class[] {
        SimpleEntity.class,
        SimpleEntityWithTransientField.class,
        TwoFieldEntity.class
    };

    @Theory
    public void classHasValidConfiguration(Class<?> entityClass) {

        new AnnotationConfiguration().addAnnotatedClass(entityClass).buildMappings();
    }
}