如何使用@Autowired 字段测试通用抽象类？

Question

我有包含@Autowired 字段的通用抽象类 AbstractBaseEntityGenericDao。它工作得很好，直到我不得不为它编写一个单元测试，而不是在扩展它的类的所有测试中复制相同的代码。现在我在想...是否可以为此类编写单元/集成测试？

@Repository
@Transactional
public abstract class AbstractBaseEntityGenericDao<T extends BaseEntity> {

    private Class<T> classInstance;

    private SessionFactory sessionFactory;

    @Autowired
    public void setSessionFactory(SessionFactory sessionFactory) {
        this.sessionFactory = sessionFactory;
    }

    public final void setClassInstance(Class<T> clasInstance) {
        this.classInstance = clasInstance;
    }

    public void create(@NonNull T entity) {
        Session session = sessionFactory.getCurrentSession();
        session.save(entity);
    }

    public Optional<T> find(long id) {
        Session session = sessionFactory.getCurrentSession();
        return Optional.ofNullable(session.get(classInstance, id));
    }

    public void update(@NonNull T entity) {
        Session session = sessionFactory.getCurrentSession();
        session.saveOrUpdate(entity);
    }

    public void remove(@NonNull Long id) throws EntityNotFoundException {
        Session session = sessionFactory.getCurrentSession();
        session.remove(session.load(classInstance, id));
    }

    public void remove(@NonNull T entity) {
        Session session = sessionFactory.getCurrentSession();
        session.remove(entity);
    }
}

Answer 1

这很困难的原因是因为通常你不应该这样做。抽象类应该不知道它的子类如何创建SessionFactory。所以它应该看起来像：

@Repository
@Transactional
public abstract class AbstractBaseEntityGenericDao<T extends BaseEntity> {

    ...        

    protected SessionFactory sessionFactory;

    ...
}

现在你不能直接对抽象类进行单元测试，因为它不能被实例化。但是，您可以在单元测试中将其存根，并测试该存根。存根反过来将有一个受保护字段的构造函数，我们可以在单元测试中模拟出来。最后它看起来像：

public class AbstractBaseEntityGenericDaoTest {

    private class AbstractClassStub extends AbstractBaseEntityGenericDao {

        public AbstractClassStub(SessionFactory sessionFactory) {
            this.sessionFactory = sessionFactory;
        }

        @Override
        public void create(BaseEntity entity) {
            super.create(entity);
        }

        @Override
        public Optional find(long id) {
            return super.find(id);
        }

        @Override
        public void update(BaseEntity entity) {
            super.update(entity);
        }

        @Override
        public void remove(@NonNull Long id) throws EntityNotFoundException {
            super.remove(id);
        }

        @Override
        public void remove(BaseEntity entity) {
            super.remove(entity);
        }
    }

    @Mock
    SessionFactory sessionFactory;

    private AbstractClassStub abstractClassStub;

    @Before
    public void before() {
        sessionFactory = mock(SessionFactory.class);
        abstractClassStub = new AbstractClassStub(sessionFactory);
    }

    @Test
    public void testWhatever() {
        abstractClassStub.find(1); //or whatever
    }
}