Mapstruct : Ambiguous mapping methods found for mapping collection element

Question

I have two methods for mapping entity to domain.

RDomain entityToDomain(REntity rEntity)

/*
this method ignores some of the fields in the domain.
*/
RDomain entityToDomainLight(REntity rEntity)

I'm getting Ambiguous mapping methods found for mapping collection element when I try to define mapping method for List of entities to domains.

List<RDomain> entitiesToDomains(List<REntity> rEntities)

Is there a way to define which method to use for mapping collection of objects

score 40 · Accepted Answer · answered Apr 23 '19 at 16:06

40

As @Filip suggested, it is better to do something like that :

RDomain entityToDomain(REntity rEntity)

@Named(value = "useMe")
RDomain entityToDomainLight(REntity rEntity)

@IterableMapping(qualifiedByName = "useMe")
List<RDomain> entitiesToDomains(List<REntity> rEntities)

answered Apr 23 '19 at 16:06

ihebiheb

3,673
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1

Solved by `@Named(value = "useMe")` – Sham Fiorin Aug 25 '21 at 15:21

score 0 · Answer 2 · answered Mar 18 '18 at 10:23

0

As far as I understand Mapstruct, there is no wo to tell a mapper

List<RDomain> entitiesToDomains(List<REntity> rEntities)

which of your to mapping methods it should use. But you can implement entitiesToDomains as a Java 8 default method on your mapper interface.

default List<RDomain> entitiesToDomains(List<REntity> rEntities) {

    List<RDomain> domains = new ArrayList<>();

    for(REntity r : rEntities) {
       //delegate to your dedicated mapper
       domains.add(entityToDomainLight(r));
    }

    return domains;

}

answered Mar 18 '18 at 10:23

saw303

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12

You can actually achieve that by using [`IterableMapping#qualifiedByName`](http://mapstruct.org/documentation/stable/api/org/mapstruct/IterableMapping.html#qualifiedByName--) or [`IterableMapping#quelifiedBy`](http://mapstruct.org/documentation/stable/api/org/mapstruct/IterableMapping.html#qualifiedBy--). It is in the documentation, but not that exposed :) – Filip Mar 18 '18 at 21:10
Cool. I did not know that. Going to update by answer – saw303 Mar 19 '18 at 05:24
2

Of course you would need to put a qualifier (MapStruct one) on the entity mapper methods – Filip Mar 19 '18 at 06:05

Mapstruct : Ambiguous mapping methods found for mapping collection element

2 Answers2