JPA Lazy mapping

[Jorge Martins]

I'm using mapstruct to map hibernate entities to DTO's and the inverse.

The mappings are working very well, however I'm still struggling with lazy/eager mappings.

In some cases I want to map a lighter version of the entity (without fetching collections). In some other cases I want to map fetching some of the collections.

To do that I was thinking to use different versions of mappings, ignoring the collections when I don't want to fetch.

I try to do that using custom qualifiers: @LazyMapping and @EagerMapping

@EagerMapping

@Mappings({

@Mapping(target = "description", source = "sampleNested.description"),

@Mapping(target = "attributes", source = "sampleNested.attributes"),

@Mapping(target = "somecollection", source = "collectionxpto") })

SampleDTO sampleDtoToEntity(SampleEntity sampleEntity);

@LazyMapping

@InheritConfiguration

@Mapping(target = "somecollection", ignore = true) //MARK AS IGNORED

SampleDTO lazySampleDtoToEntity(SampleEntity sampleEntity);

@IterableMapping(qualifiedBy=EagerMapping.class)

List<SampleDTO> samplesDtoToEntities(List<SampleEntity> sampleEntities);

@IterableMapping(qualifiedBy=LazyMapping.class)

List<SampleDTO> lazySamplesDtoToEntities(List<SampleEntity> sampleEntities);

However in some cases I'm getting error for ambiguos mappings.

Is this the correct approach? How can I do this with mapstruct?

Thank you

[Gunnar Morling]

Hi Jorge,

The general approach looks good. In which cases exactly do you get the
ambiguous method error? Can you share a complete example, e.g. by
forking the https://github.com/mapstruct/mapstruct-examples repo and
taking one of the examples as starting point?

Thanks,

--Gunnar