mapstruct/mapstruct-users

Hi everyone, i have a custom case that some of my dto's have a field of type X, and i need to map this class to Y by using a spring service method call(i do a transactional db operation and return an instance of Y). But in this scenario i also need to use existing value of Y field. Let me explain it by example.

// DTO
public class AnnualLeaveRequest {
    private FileInfoDTO annualLeaveFile;
}

//ENTITY
public class AnnualLeave  {

    @OneToOne
    private FileReference annualLeaveFile;
}

@Mapper
public abstract class FileMapper {
    @Autowired
    private FileReferenceService fileReferenceService;

    public FileReference toFileReference(@MappingTarget FileReference fileReference, FileInfoDTO fileInfoDTO) {
        return fileReferenceService.updateFile(fileInfoDTO, fileReference);
    }
}

//ACTUAL ENTITY MAPPER
@Mapper(uses = {FileMapper.class})
public interface MazeretIzinMapper {
    AnnualLeave toEntity(AnnualLeaveRequest dto);
}

// WHAT IM TRYING TO ACHIEVE
@Component
public class MazeretIzinMapperImpl implements tr.gov.hmb.ikys.personel.izinbilgisi.mazeretizin.mapper.MazeretIzinMapper {

    @Autowired
    private FileMapper fileMapper;

    @Override
    public AnnualLeave toEntity(AnnualLeaveRequest dto) {
        AnnualLeave entity = new AnnualLeave();
        entity.setAnnualLeaveFile(fileMapper.toFileReference(dto.getAnnualLeaveFile(), entity.getAnnualLeaveFile()));
        return entity;
    }

    @Override
    public void updateEntity(AnnualLeave entity, AnnualLeaveUpdateRequest dto) {
        entity.setAnnualLeaveFile(fileMapper.toFileReference(dto.getAnnualLeaveFile(), entity.getAnnualLeaveFile()));
    }
}

But mapstruct ignores the result of "FileReference toFileReference(@MappingTarget FileReference fileReference, FileInfoDTO fileInfoDTO) " and does not map the result of it to the actual entity's FileReference field. Do you have any idea for resolving this problem?