MapStruct(model和DTO之间的完美转换)的使用

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• 我的地址：https://www.jianshu.com/u/a5153fbb0434

本文的代码地址：GitHub MapStruct Demo

有 Enum 类型

MapStruct 可以非常轻松的将 Bean 对象映射到 DTO 对象中用于传输。
MapStruct会在编译阶段实现其接口。

要是 Bean 中有 Enum 类型，需要去对应 DTO 中的String ，需要注意以下几点：
Bean 中重写 setType(String type) 方法
DTO 中重写 setType(CarType carType) 方法

1.Bean

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Car {
    private String make;
    private int numberOfSeats;
    private CarType type;

    public void setType(String type) {
        this.type = CarType.convert(type);
    }
}

2.Dto

@Data
@AllArgsConstructor
@NoArgsConstructor
public class CarDto {
    private String make;
    private int seatCount;
    private String type;
    private String description;

    public void setType(CarType carType) {
        this.type = carType.getType();
    }
}

3.mapstruct接口

@Mapper(
        componentModel = "spring",
        nullValueCheckStrategy = ALWAYS,
        nullValueMappingStrategy = RETURN_DEFAULT)
public interface CarMapper {
    CarMapper INSTANCE = Mappers.getMapper(CarMapper.class);

    @Mappings({
            @Mapping(source = "numberOfSeats", target = "seatCount"),
            @Mapping(target = "description", ignore = true)
    })
    CarDto carToCarDto(Car car);

    Car carDtoToCar(CarDto carDto);
}

4.TEST

@RunWith(SpringRunner.class)
@SpringBootTest
@Slf4j
public class MapstructApplicationTests {

    @Autowired
    private CarMapper carMapper;

    @Test
    public void mapCarToDto() {
        //given
        Car car = new Car("Morris", 5, CarType.SAIC);

        //when
        CarDto carDto = carMapper.carToCarDto(car);

        //then
        Assert.assertNotNull(carDto);
        Assert.assertEquals("Morris", carDto.getMake());
        Assert.assertEquals("上汽", carDto.getType());
        log.info("输出的CarDto是：{}", JSON.toJSONString(carDto));
    }
    @Test
    public void carDtoToBean(){
        CarDto carDto = new CarDto("Morris",10,"奥迪","真的很不错");

        Car car = carMapper.carDtoToCar(carDto);
        log.info("输出的Car是：{}",JSON.toJSONString(car));
    }

}

枚举类：

@Getter
public enum CarType {
    BMW(1, "宝马"),
    AUDI(2, "奥迪"),
    SAIC(3, "上汽");

    private Integer code;
    private String type;

    CarType(Integer code, String type) {
        this.code = code;
        this.type = type;
    }

    public static CarType convert(String type) {

        switch (type) {
            case "宝马":
                return BMW;
            case "奥迪":
                return AUDI;
            case "上汽":
                return SAIC;
        }
        return null;
    }
}

参考文献

http://mapstruct.org/