How to use inheritance with ModelMapper's PropertyMap

Question

I have been using the ModelMapper to convert Identity objects (entities) with DTO objects. I want to implement generic property conversions in a generic class for all entities (GenericEToDtoPropertyMap) and explicit property conversions in separate child-classes for each entity (PersonEToDTOPropertyMap for entity Person). To make it more clear, this is my code:

Generic property map:

public class GenericEToDtoPropertyMap<E extends Identity, DTO extends PersistentObjectDTO> extends PropertyMap<E, DTO> {

  @Override
  protected void configure() {
    // E.oid to DTO.id conversion
    map().setId(source.getOid());
  }

}

Specific property map for entity Person:

public class PersonEToDTOPropertyMap extends GenericEToDtoPropertyMap<Person, PersonDTO> {

  @Override
  protected void configure() {
    super.configure();
    // implement explicit conversions here
  }

}

Usage of property map:

modelMapper = new ModelMapper();
Configuration configuration = modelMapper.getConfiguration();
configuration.setMatchingStrategy(MatchingStrategies.STRICT);
modelMapper.addMappings(new PersonEToDTOPropertyMap());
// convert person object
PersonDTO personDto = modelMapper.map(person);

The problem is that the generic conversions do not apply. In my case person.oid does not get copied to personDto.id. It works correctly only if I remove the part:

map().setId(source.getOid());

from the GenericEToDtoPropertyMap.configure() method and put it in the PersonEToDTOPropertyMap.configure() method.

I guess, it has something to do with ModelMapper using Reflection to implement the mappings, but it would be nice if I could use inheritance in my property maps. Do you have any idea how to do this?

score 1 · Accepted Answer · answered Jan 13 '17 at 11:54

I just found an answer from the creator of ModelMapper, Jonathan Halterman: https://groups.google.com/forum/#!topic/modelmapper/cvLTfqnHhqQ

This sort of mapping inheritance is not currently possible.

So I guess I have to implement all conversions in the child-class

Ing. JC · Answer 2 · 2022-01-31T06:47:34.240

Well after 5 years... I got a solution (I have same problem)

After view some post and search answers I found this post The problem happen because the method "configure()" restricts what you can do inside so I thinking in create an method outside for get the custom format, so this is my code:

public class UserMap extends PropertyMap<User,UserLoginDTO> {
    @Override
    protected void configure() {
        using(generateFullname()).
                map(source,destination.getFullName());
    }

    private Converter<User, String> generateFullname(){
        return    context -> {
            User user = context.getSource();
        return user.getName()+ " " + user.getFirstLastname() + " " + user.getSecondLastname();
    };
    }

}

so you could call it from your main method or wherever you need, like this:

ModelMapper modelMapper=new ModelMapper();
modelMapper.addMappings(new UserMap());

and the output is:

 UserLoginDTO{id='001', fullName='Jhon Sunderland Rex'}

How you can see, the logic is out of configure method and it works, I hope this helps for others

pd: sorry for my english

How to use inheritance with ModelMapper's PropertyMap

2 Answers2