nullValuePropertyMappingStrategy not working

user_5228754 0
Viewed 2243

I have the following mapper

@Mapper(config = MappingConfig.class)
public interface PokerRoomMapper {

  @Mapping(target = "phase", nullValuePropertyMappingStrategy = NullValuePropertyMappingStrategy.IGNORE)
  PokerRoom pokerRoomDtoToPokerRoom(PokerRoomDto pokerRoomDto);

}

The pokerRoomDto which is passed to it has a "phase" field which can be null. I want this field to be ignored when it is null. But right now the "null" value still gets mapped to the pokerRoom entity.

If I just ignore the field in the mapper it works and the default value for phase in PokerRoom stays untouched however I dont want to always ignore it.

@Mapper(config = MappingConfig.class)
public interface PokerRoomMapper {

  @Mapping(target = "phase", ignore = true)
  PokerRoom pokerRoomDtoToPokerRoom(PokerRoomDto pokerRoomDto);

}
mapstruct java
2 Answers

This works as designed. NullValuePropertyMappingStrategy is only applied to update method. It is not used for normal mappings.

I think that you are looking for NullValueCheckStrategy, if you use NullValueCheckStrategy#ALWAYS then MapStruct will always do a null check non the PokerRoomDto and only invoke the setter on the PokerRoom if the value was not null

user_11154910

If you initialise your field at declaration and want to keep that value, I've come up with a solution. A bit hacky, not very general (depends on generated variable name), but works. Assuming:

class PokerRoom {
    Integer phase = 0;
}

You can use

@Mapping(target = "phase", defaultExpression = "java( pokerRoom.getPhase() )")
PokerRoom pokerRoomDtoToPokerRoom(PokerRoomDto pokerRoomDto);

A simpler solution would be to use the same constant you use at field declaration.

@Mapping(target = "phase", defaultValue = "0")
PokerRoom pokerRoomDtoToPokerRoom(PokerRoomDto pokerRoomDto);
user_92749480
Related