我要用mapstrout和javaMap两个对象：

@Data
@NoArgsConstructor
public class EventDTO {

  @JsonInclude(Include.NON_NULL)
  private EventStatusDTO eventStatus;
}

@Data
@NoArgsConstructor
public class EventStatusDTO {

  @JsonInclude(Include.NON_NULL)
  private String statusCode;

  @JsonInclude(Include.NON_NULL)
  private String statusDescription;
}

@Data
@NoArgsConstructor
public class Event {
  private String statusCode;
}

当状态代码为null时，我希望eventstatusdto对象中的所有eventstatusdto对象都为null。但是像这样定义Map器：

@Mappings({
    @Mapping(target = "voltageLevel.voltageLevelCode", source = "voltageLevelCode"),
    @Mapping(target = "eventStatus.statusCode", source = "statusCode", nullValuePropertyMappingStrategy = NullValuePropertyMappingStrategy.SET_TO_NULL),
    @Mapping(target = "eventType.typeCode", source = "typeCode", nullValuePropertyMappingStrategy = NullValuePropertyMappingStrategy.SET_TO_NULL),
    @Mapping(target = "eventCause.causeCode", source = "causeCode", nullValuePropertyMappingStrategy = NullValuePropertyMappingStrategy.SET_TO_NULL)
  })
  public abstract EventDTO fromEntityToDTO(Event source);

我只能在eventdto中生成一个空对象eventstatusdto。
这是生成的代码：

protected EventCauseDTO eventToEventCauseDTO(Event event) {
        if ( event == null ) {
            return null;
        }

        EventCauseDTO eventCauseDTO = new EventCauseDTO();

        eventCauseDTO.setCauseCode( event.getCauseCode() );

        return eventCauseDTO;
    }

我能让这更像谁

protected EventCauseDTO eventToEventCauseDTO(Event event) {
        if ( event == null ) {
            return null;
        }

        EventCauseDTO eventCauseDTO = null;

        if(event.getCauseCode() != null) {
            eventCauseDTO = new EventCauseDTO();
            eventCauseDTO.setCauseCode(event.getCauseCode());
        }

        return eventCauseDTO;
    }

我一直在用mapstruct的一些nullvaluestrategies进行测试，但是什么都没有。。。我不想用@aftermapping检查所有空对象。
提前谢谢。