Configure ModelMapper to map nested object to field

Question

Here are my DTOs:

public class TagVolumeDTO {
    private Long id;
    private Long idTag;
    //...
}

public class TagTDO {
    private Long id;
    private Long amount;
    //...
}

and here are my entities:

public class TagVolume {
    private Long id;
    private Tag tag;
    //...
}

public class Tag {
    private Long id;
    private Long amount;
    //...
}

I would like to configure my ModelMapper to map Tag#id to TagVolumeDTO#idTag. Is that possible?

score 5 · Answer 1 · edited Jun 20 '20 at 09:12

5

Configuration:

ModelMapper mapper = new ModelMapper();
mapper.getConfiguration().setMatchingStrategy(MatchingStrategies.STRICT);
mapper.typeMap(TagVolume.class, TagVolumeDTO.class)
        .addMappings(m -> m.map(src -> src.getTag().getId(), TagVolumeDTO::setIdTag));

Usage:

Tag tag = new Tag();
tag.setId(1L);
tag.setAmount(10L);
TagVolume tagVolume = new TagVolume();
tagVolume.setId(123L);
tagVolume.setTag(tag);
System.out.println(mapper.map(tagVolume.getTag(), TagDTO.class));
System.out.println(mapper.map(tagVolume, TagVolumeDTO.class));

Output:

TagDTO(id=1, amount=10)

TagVolumeDTO(id=123, idTag=1)

ModelMapper version: 1.1.0

P.s. You can to organize your code similar to my answer in another question.

edited Jun 20 '20 at 09:12

Community

1
1

answered Dec 21 '17 at 12:15

Andrew Nepogoda

1,825
17
24

Thank you for your answer but this does not work: The destination property TagVolumeDTO.setIdTag() matches multiple source property hierarchies – Florent06 Dec 26 '17 at 10:04
@Florent06 you want to map Tag to TagVolumeDTO, right? – Andrew Nepogoda Dec 26 '17 at 10:14
I want to map Tag to TagDTO and TagVolume to TagVolumeDTO. But, as you can see in my 1st post, TagVolume as a field referenced as a Tag. But, in my DTOs, TagVolumeDTO has no reference to TagVolume. Only the Tag's id. – Florent06 Dec 26 '17 at 10:40
@Florent06, What is the match strategy of your model mapper? – Andrew Nepogoda Dec 26 '17 at 10:48
I have not set any match strategy. – Florent06 Dec 26 '17 at 16:33
1

clear and perfect answer. Thanks! – gratinierer Mar 29 '22 at 12:41

Mahendra Kapadne · Answer 2 · 2017-12-22T01:15:05.763

2

For these kind of mapping it is preferred to used AnnotationProcessor like mapStuct which reduces code.

It will generate code for Mapper

  @Mapper
public interface SimpleSourceDestinationMapper {
    TagVolumeDTO sourceToDestination(Tag source);
    Tag destinationToSource(TagVolumeDTO destination);
}

usage of these mapper is as follow

private SimpleSourceDestinationMapper mapper
      = Mappers.getMapper(SimpleSourceDestinationMapper.class);

TagVolumeDTO destination = mapper.sourceToDestination(tag);

Kindly find link for detailed implementation MapStuct

edited Dec 22 '17 at 01:15

answered Dec 21 '17 at 13:06

Mahendra Kapadne

426
1
3
10

This is not what I want. If you take a look at my objects, you'll see 2 DTOs and 2 entities. One of the entities has a field of type of the second. – Florent06 Dec 26 '17 at 10:11
What you are saying is also possible with MapStruct see this stack overflow link https://stackoverflow.com/questions/34130599/mapstruct-mapping-2-objects-to-a-3rd-one – Mahendra Kapadne Dec 26 '17 at 10:23
Thank you but I think this solution is a bit too hard to set up. Though, I can not set up it with my Junit Tests. – Florent06 Dec 27 '17 at 09:12

Configure ModelMapper to map nested object to field

2 Answers2