我尝试在Gradle中使用mapstruct，但效果有限。当我在应用程序中使用它时，一切似乎都运行良好，但当我尝试编写一些测试时，Spring无法正确自动连接MapStruct（它只返回NullPointer异常）。我使用的是Gradle 5.4.1、Junit5和IntelliJ 2019.1.2。
这是build文件夹，没有为测试类生成Map器。

代码库在这里：https://github.com/MirkoManojlovic/mapstruct-example

Map器：

@Mapper(unmappedTargetPolicy = ReportingPolicy.WARN,
        componentModel = "spring",
        injectionStrategy = InjectionStrategy.CONSTRUCTOR)
public interface ItemMapper {
    ItemDto toDto(Item item);
    Item toItem(ItemDto itemDto);
}

存储库：

public class ItemRepository {
    public ItemDto getItemDto() {
        return new ItemDto("item 1");
    }

    public Item getItem() {
        return new Item(1, "item 1", 20);
    }
}

服务：

@Service
@RequiredArgsConstructor
@Log4j2
public class ItemService {
    private final ItemRepository itemRepository;
    private final ItemMapper itemMapper;

    public ItemDto getItemDto() {
        Item item = itemRepository.getItem();
        ItemDto itemDto = itemMapper.toDto(item);
        log.info(itemDto);
        return itemDto;
    }

    public Item getItem() {
        ItemDto itemDto = itemRepository.getItemDto();
        Item item = itemMapper.toItem(itemDto);
        log.info(item);
        return item;
    }
}

测试：

@ExtendWith(MockitoExtension.class)
public class ItemServiceTest {

    @Mock
    private ItemRepository itemRepository;

    @InjectMocks
    private ItemService itemService;

    @Spy
    private ItemMapper itemMapper;

    @Test
    void shouldReturnItemDto() {
        Item mockItem = new Item(1, "mockItem", 10);
        given(itemRepository.getItem()).willReturn(mockItem);
        ItemDto itemDto = itemService.getItemDto();
        assertThat(mockItem.getName()).isEqualTo(itemDto.getName());
    }

}

版本分级：

plugins {
    id 'org.springframework.boot' version '2.1.5.RELEASE'
    id 'java'
}

apply plugin: 'io.spring.dependency-management'

group = 'com.mapstruct.spring.example'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '1.8'

configurations {
    compileOnly {
        extendsFrom annotationProcessor
    }
}

repositories {
    mavenCentral()
}

test {
    useJUnitPlatform {
    }
}

dependencies {
    // Mapstruct
    implementation 'org.mapstruct:mapstruct:1.3.0.Final'
    annotationProcessor 'org.mapstruct:mapstruct-processor:1.3.0.Final'
    testAnnotationProcessor 'org.mapstruct:mapstruct-processor:1.3.0.Final'

    implementation 'org.springframework.boot:spring-boot-starter-web'
    compileOnly 'org.projectlombok:lombok'
    annotationProcessor 'org.projectlombok:lombok'

    testImplementation('org.springframework.boot:spring-boot-starter-test')

    // JUnit5
    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.3.2'
    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.3.2'
    testImplementation 'org.junit.jupiter:junit-jupiter-params:5.3.2'

    // Mockito
    testImplementation 'org.mockito:mockito-core:2.23.4'
    testImplementation 'org.mockito:mockito-junit-jupiter:2.23.4'
}