public interface PersonCreationStrategy {
Person create(PersonCreateCommand command);

}

public class PersonCreateCommand {

private String type;
private Map<String , String> params;

}

public class PersonService {

private final Map<String, PersonCreationStrategy> creationStrategies;

public Person create(PersonCreateCommand command) {
    PersonCreationStrategy creationStrategy = creationStrategies.get(command.getType());
    if (creationStrategy == null) {
        throw new UnsupportedTypeException("unsupported type " + command.getType());
    }
    Person person = creationStrategy.create(command);
    return person;
}

}

I have in my app strategy pattern to store into database different type of classes , my main class is Person and other classes inheritance after Person , Person class store all type in SINGLE_TABLE ,

And now I need to do DTO for child classes cause I need return additional values .

Someone could explain it to me ? how to do it in good way ?