Subclass Repository returns also Superclass objects [DATAMONGO-1142]

Mateusz Rasiński opened DATAMONGO-1142 and commented

Having two types of entities, that are mapped to two Java classes in the single MongoDB collection:

@Document
public class Superclass { ... }

@Document(collection = "superclass")
public class Subclass extends Superclass { ... }

and two repositories for those entities:

public interface SuperclassRepository extends MongoRepository<Superclass, String> {}
public interface SubclassRepository extends MongoRepository<Subclass, String> {}

MongoRepositories don't handle the inheritance of the entities correctly. While querying for all Subclass objects (e.g. SubclassRepository.findAll()) the result set contains Superclass objects, that are instantiated (or at least have been tried to be instantiated) with null values for fields that are part of the Subclass, but are not part of the Superclass.

The expected result would be that SubclassRepository should return only Subclass objects, while SuperclassRepository should return Superclass and Subclass objects. It works this way in Spring Data JPA

Affects: 1.6.1 (Evans SR1)

Reference URL: http://stackoverflow.com/questions/28025710/spring-data-mongodb-repositories-dont-implement-inheritance-correctly

Referenced from: pull request https://github.com/spring-projects/spring-data-mongodb/pull/266

4 votes, 7 watchers