#Mapping on mapstruct with List<> Of List<> - mapstruct

Question

I've recently started to use mapstruct, while coding I stuck with a scenario. In order to solve the ambiguity between the below default methods, I'm trying to use the "qualifiedBy" on a List<
#Mapping(qualifiedBy = LineTestBO). Line => 1
List<ReturnABO> toCaptureLineItemsBOs(List<LineDTO> lineDTO);
#Named("LineTestBO")
default ReturnABO map(LineDTO lineDTO) {
if (lineDTO.getCurrency() != null && lineDTO.getNationalPermit() != null &&
lineDTO.getAmount() != null && lineDTO != null)
return this.toBO(lineDTO);
return null;
}
default returnABO toBO(LineDTO lineDTO) {
// To do here
}
But Line 1 shows the error as it needs to "target" to be specified. I'm not sure what should be the target here since Line is a collection object. Even If I don't use the #mapping the mapstuct generates the mapper implementation. I read the mapstuct documentation but could not follow much for this scenario. How the Named annotation can be used on List to explicity denote that this is name to be used ? Can someone help me? Thanks.

Answer 1

the target must be specified, so if your POJOs look like this
class A {
private List<ReturnABO> x;
}
class B {
private List<LineDTO> x;
}
in your mapper, you could have something like this
interface AMapper {
#Mapping(target="x", source="x", qualifiedByName = "LineTestBO")
A toA(B b);
#Named("LineTestBO")
default List<ReturnABO> lineTestBO (List<LineDTO> lines) {
return lines.stream().map(this::map).collect(Collectors.toList())
}
default ReturnABO map(LineDTO lineDTO) {
if (lineDTO.getCurrency() != null && lineDTO.getNationalPermit() != null &&
lineDTO.getAmount() != null && lineDTO != null)
return this.toBO(lineDTO);
return null;
}
}

Answer 2

The reason for the error is that using #Mapping on iterable mapping method doesn't make much sense.
What you are looking for is IterableMapping#qualifiedBy.
So in your case the mapper needs to look like:
#Mapper
public interface MyMapper {
#IterableMapping(qualifiedByName = "LineTestBO")
List<ReturnABO> toCaptureLineItemsBOs(List<LineDTO> lineDTO);
#Named("LineTestBO")
default ReturnABO map(LineDTO lineDTO) {
if (lineDTO.getCurrency() != null && lineDTO.getNationalPermit() != null && lineDTO.getAmount() != null && lineDTO != null) {
return this.toBO(lineDTO);
}
return null;
}
default returnABO toBO(LineDTO lineDTO) {
// To do here
}
}