Envers: Allow to extend the default EnversRevisionRepositoryImpl

[TMRGZ]

Recently in my job I had to expand the functionality of the RevisionRepository and I thought that could be great if this posibility is added to the Spring Data project.

To achieve this, I added the following method to the EnversRevisionRepositoryFactoryBean, treating it as if we were modifying the revision entity:

public void setRepositoryImplClass(Class<? extends EnversRevisionRepositoryImpl<T, S, N>> repositoryImplClass) {
    this.repositoryImplClass = repositoryImplClass;
}

This ensures the default behavior when the new parameter is null:

private static class RevisionRepositoryFactory<T, ID, N extends Number & Comparable<N>> extends JpaRepositoryFactory {

    private final Class<?> repositoryClass;

    public RevisionRepositoryFactory(EntityManager entityManager, Class<?> revisionEntityClass, Class<?> repositoryImplClass) {

        // original implementation

        this.repositoryClass = repositoryImplClass != null ? repositoryImplClass : EnversRevisionRepositoryImpl.class;
    }

    @Override
    protected RepositoryFragments getRepositoryFragments(RepositoryMetadata metadata) {

        Object fragmentImplementation = getTargetRepositoryViaReflection(
                repositoryClass,
                getEntityInformation(metadata.getDomainType()),
                revisionEntityInformation,
                entityManager
        );

        // original implementation
    }
}

Additionally, to maintain consistency with the return types of the original repository implementation, I changed the visibility of these methods and classes to protected:

public class EnversRevisionRepositoryImpl<T, ID, N extends Number & Comparable<N>>
        implements RevisionRepository<T, ID, N> {

    protected AuditOrder mapRevisionSort(RevisionSort revisionSort)

    protected List<AuditOrder> mapPropertySort(Sort sort)

    protected AuditQuery createBaseQuery(ID id)

    protected Revision<N, T> createRevision(QueryResult<T> queryResult)

    protected static class QueryResult<T> {
        protected QueryResult(Object[] data)
        protected RevisionMetadata<?> createRevisionMetadata()
        protected static RevisionMetadata.RevisionType convertRevisionType(RevisionType datum)
    }

}

Feel free to provide comments or advice in case I've attempted to reinvent the wheel or if there's an easier way to achieve this exact functionality