MapStruct中的通用映射器函数

Question

@Data
public class CarDto {
    private String make;
    private String model;
    private int year; 
}

@Data
public class Car {
    private MakeEnum make;
    private String model;
    private int year;   
}

@Mapper
public interface CarMapper {
   CarMapper INSTANCE = Mappers.getMapper(CarMapper.class);
   Car toModel(CarDto carDto);
   CarDto toDto(Car carModel);
}

// Using mapper
Car carModel = CarMapper.INSTANCE.toModel(carDto);

  Car carModel = Mapper.map(carDto, Car.class);

怎么做？没有找到可以基于类型动态映射的示例。我发现这种方法在ModelMapper、GoogleGSON中都非常方便。感谢你的帮助！

Answer 1

在调用映射之前，您必须像下面这样设置和接口MapStruct：

@Mapper(componentModel = "spring")
public interface MapStructMapper {

    ObjectDto objectToObjectDto(Object object);

}

然后是它的一个实现：

@Component
public class MapStructMapperImpl implements MapStructMapper {

    @Override
    public ObjectDto objectToObjectDto(Object object) {

        if ( object == null ) { return null; }

        ObjectDto objectDto = new ObjectDto();
        objectDto.setId( object.getId() );
        objectDto.setName( object.getName() );

        return objectDto;
    }

然后，您只需将这个接口注入到控制器中，并像这样调用存储库：

@RequestMapping("/objects")
public class ObjectController {

    private MapStructMapper mapstructMapper;

    private ObjectRepository objectRepository;

    @Autowired
    public ObjectController(
            MapStructMapper mapstructMapper,
            ObjectRepository objectRepository
    ) {
        this.mapstructMapper = mapstructMapper;
        this.objectRepository = objectRepository;
    }

    @GetMapping("/{id}")
    public ResponseEntity<ObjectDto> getById(@PathVariable(value = "id") int id){
        return new ResponseEntity<>(
                mapstructMapper.objectToObjectDto(
                        objectRepository.findById(id).get()
                ),
                HttpStatus.OK
        );
    }
    
}