测试基于CrudRepository的ExpeditionService时Repository注入为空的解决方法

出现Repository为空的核心原因是：你手动实例化ExpeditionService时，Spring的测试上下文并没有将它管理的Repository代理实例注入进去——手动new的对象不在Spring容器的管控范围内，自然无法自动填充依赖。以下是几种可行的解决方式：

方式1：让Spring自动注入ExpeditionService（推荐） #

放弃手动实例化，直接在测试类中通过@Autowired注入ExpeditionService，前提是你的ExpeditionService已经是Spring管理的Bean（比如标注了@Service注解）。

示例代码：

@DataJpaTest
class ExpeditionServiceTest {
    @Autowired
    private ExpeditionService expeditionService;

    // 按需注入Repository，用于测试数据准备
    @Autowired
    private ArticleRepository articleRepository;

    @Test
    void testExpeditionLogic() {
        // 编写测试逻辑
    }
}

对应的ExpeditionService需要是Spring组件，且用构造函数注入依赖（这是Spring推荐的依赖注入方式）：

@Service
public class ExpeditionService {
    private final ArticleRepository articleRepository;
    private final CustomerRepository customerRepository;
    private final AddressRepository addressRepository;

    public ExpeditionService(ArticleRepository articleRepository,
                            CustomerRepository customerRepository,
                            AddressRepository addressRepository) {
        this.articleRepository = articleRepository;
        this.customerRepository = customerRepository;
        this.addressRepository = addressRepository;
    }

    // 业务方法实现
}

方式2：手动从Spring上下文获取Repository并初始化Service #

如果因特殊需求必须手动实例化ExpeditionService，可以先通过@Autowired获取Spring管理的Repository实例，再在测试初始化阶段传入Service的构造函数：

@DataJpaTest
class ExpeditionServiceTest {
    @Autowired
    private ArticleRepository articleRepository;
    @Autowired
    private CustomerRepository customerRepository;
    @Autowired
    private AddressRepository addressRepository;

    private ExpeditionService expeditionService;

    @BeforeEach
    void setUp() {
        expeditionService = new ExpeditionService(articleRepository, customerRepository, addressRepository);
    }

    @Test
    void testExpeditionLogic() {
        // 编写测试逻辑
    }
}

方式3：确保Spring能扫描到ExpeditionService #

如果测试类和ExpeditionService不在同一包或子包下，Spring可能无法自动扫描到它。此时可以在@DataJpaTest上添加@Import注解，显式指定要加载的Service类：

@DataJpaTest
@Import(ExpeditionService.class)
class ExpeditionServiceTest {
    @Autowired
    private ExpeditionService expeditionService;

    // ...测试方法
}

内容的提问来源于stack exchange，提问作者fnyve