[嘲笑QueryBuilder时为NullPointerException

Question

问题：

我正在尝试使用Mockito创建测试。此测试将模拟QueryBuilder，并尝试验证是否一切正常。但是我得到了[[“ java.lang.NullPointerException”。似乎尚未初始化，但是我看不到它是什么。

代码：

@RunWith(MockitoJUnitRunner.StrictStubs.class)
public class AcademicJPADAOTest {

    @Mock
    private EntityManager entityManager;
    @Mock
    private CriteriaBuilder cb;
    @Mock
    private CriteriaQuery<Academic> cq;
    @Mock
    private Root<Academic> root;

    @InjectMocks
    AcademicJPADAO academicjpadao;

    private String passwdcode = "83997689-22b6-4a7e-a801";


    @Test
    public void retrieveByPasswordCodeTest() throws PersistentObjectNotFoundException, MultiplePersistentObjectsFoundException {

        Academic academic = new Academic();

        when(entityManager.getCriteriaBuilder()).thenReturn(cb);
        when(cb.createQuery(Academic.class)).thenReturn(cq);
        when(cq.from(Academic.class)).thenReturn(root);
        when(cq.where(cb.equal(root.get(Academic_.passwordCode), passwdcode))).thenReturn(cq);

        when(academicjpadao.getEntityManager().createQuery(cq).getSingleResult()).thenReturn(academic);

        academicjpadao.retrieveByPasswordCode(passwdcode);

        verify(entityManager, times(1)).getCriteriaBuilder();

    }
}

行错误：

when(academicjpadao.getEntityManager().createQuery(cq).getSingleResult()).thenReturn(academic);

Answer 1

也许您的academicjpadao在此部分中未正确注入：

 @InjectMocks
 AcademicJPADAO academicjpadao;

因此，请使用MockitoAnnotations.initMocks来启动@Mock和@InjectMocks对象。因此，您必须将此方法添加到类中：
@Before
public void setup() {
    MockitoAnnotations.initMocks(this);
}