如何使用 String 和 class 作为参数为 EntityManger createNativeQuery 编写 Junit 测试用例

Question

@Repository
public class DesignatorDaoImpl extends GenericDaoImpl implements DesignatorDao {

    @Autowired
    EntityManager em;

    public List<Designator> getDesignators(DesignatorRequestDTO dto) throws Exception {
        List<Designator> designatorsList = new ArrayList<>();
        int start = dto.getStart();
        String queryString ="select * from ( SELECT * FROM TAB.DESIGNATOR WHERE ACTIVE_IND ='A' ORDER BY LAST_EDITED_DATE DESC ) OFFSET "+ start +" ROWS FETCH NEXT "+dto.getLimit()+" ROWS ONLY";          
        Query query = em.createNativeQuery(queryString,Designator.class);
        designatorsList = query.getResultList();
        return designatorsList;
    }
}

I have the above class to get records from DB. I wrote JUnit test for this above class as

@Transactional
@Rollback(true)
public class DesignatorDaoImplTest {

    @Mock
    EntityManager entityManagerMock;

    @Mock
    TypedQuery<Designator> getQuery;

    @InjectMocks
    DesignatorDaoImpl designatorDaoImpl;

    DesignatorRequestDTO dto = new DesignatorRequestDTO();

    List<Designator> designatorEntityList = new ArrayList<>();

    @Before
    public void setUp() throws Exception { 
        MockitoAnnotations.initMocks(this);
        dto.setLimit(4);
        dto.setStart(1);

        Designator entity = new Designator();
        entity.setId("dgbkk");
        designatorEntityList.add(entity);
    }

    @Test
    public void saveDesignatorTest() throws Exception {
        Mockito.when(entityManagerMock.createNamedQuery(ArgumentMatchers.anyString(), ArgumentMatchers.eq(Designator.class))).thenReturn(getQuery);
        Mockito.when(getQuery.getResultList()).thenReturn(designatorEntityList);
        assertNotNull(designatorDaoImpl.saveDesignators(dto));
    }
}

I have problem mocking and at this em.createNativeQuery(queryString,Designator.class) in dao class I am getting null . How can I properly mock the em.createNativeQuery in test class?

Answer 1

According to the documentation, if you are using argument matchers, all arguments have to be provided by matchers . Hence, try using ArgumentMatchers.eq() ( reference documentation ) to check for Designator.class equality:

@Mock
TypedQuery<Designator> getQuery;

@Test
public void saveDesignatorTest() throws Exception {
    Mockito.when(entityManagerMock.createNamedQuery(ArgumentMatchers.anyString(), ArgumentMatchers.eq(Designator.class))).thenReturn(getQuery);
    Mockito.when(getQuery.getResultList()).thenReturn(designatorEntityList);
    assertNotNull(designatorDaoImpl.getDesignators(dto));
}

---

Avoid using property injection and use constructor injection instead:

@Repository
public class DesignatorDaoImpl extends GenericDaoImpl implements DesignatorDao {

    private EntityManager em;

    public DesignatorDaoImpl(EntityManager em) {
        super();
        this.em = em;
    }

    public List<Designator> getDesignators(DesignatorRequestDTO dto) throws Exception {
        List<Designator> designatorsList = new ArrayList<>();
        int start = dto.getStart();
        String queryString ="select * from ( SELECT * FROM TAB.DESIGNATOR WHERE ACTIVE_IND ='A' ORDER BY LAST_EDITED_DATE DESC ) OFFSET "+ start +" ROWS FETCH NEXT "+dto.getLimit()+" ROWS ONLY";          
        Query query = em.createNativeQuery(queryString,Designator.class);
        designatorsList = query.getResultList();
        return designatorsList;
    }
}

Then you need to drop @InjectMocks because you are injecting them before being initialized and create the instance of DesignatorDaoImpl to test in the @Before method:

@Transactional
@Rollback(true)
public class DesignatorDaoImplTest {

    @Mock
    EntityManager entityManagerMock;

    @Mock
    TypedQuery<Designator> getQuery;

    DesignatorDaoImpl designatorDaoImpl;

    DesignatorRequestDTO dto = new DesignatorRequestDTO();
    List<Designator> designatorEntityList = new ArrayList<>();

    @Before
    public void setUp() throws Exception { 
        MockitoAnnotations.initMocks(this);
        
        dto.setLimit(4);
        dto.setStart(1);

        Designator entity = new Designator();
        entity.setId("dgbkk");
        designatorEntityList.add(entity);

        designatorDaoImpl = new DesignatorDaoImpl(entityManagerMock);
    }

    @Test
    public void saveDesignatorTest() throws Exception {
        Mockito.when(entityManagerMock.createNamedQuery(ArgumentMatchers.anyString(), ArgumentMatchers.eq(Designator.class))).thenReturn(getQuery);
        Mockito.when(getQuery.getResultList()).thenReturn(designatorEntityList);
        assertNotNull(designatorDaoImpl.saveDesignators(dto));
    }
}

---

If you can't change DesignatorDaoImpl then use @RunWith(MockitoJUnitRunner.class) instead of MockitoAnnotations.initMocks(this); as follows:

@Transactional
@Rollback(true)
@RunWith(MockitoJUnitRunner.class)
public class DesignatorDaoImplTest {

    @Mock
    EntityManager entityManagerMock;

    @Mock
    TypedQuery<Designator> getQuery;

    @InjectMocks
    DesignatorDaoImpl designatorDaoImpl;

    DesignatorRequestDTO dto = new DesignatorRequestDTO();

    List<Designator> designatorEntityList = new ArrayList<>();

    @Before
    public void setUp() throws Exception { 
        MockitoAnnotations.initMocks(this);
        dto.setLimit(4);
        dto.setStart(1);

        Designator entity = new Designator();
        entity.setId("dgbkk");
        designatorEntityList.add(entity);
    }

    @Test
    public void saveDesignatorTest() throws Exception {
        Mockito.when(entityManagerMock.createNamedQuery(ArgumentMatchers.anyString(), ArgumentMatchers.eq(Designator.class))).thenReturn(getQuery);
        Mockito.when(getQuery.getResultList()).thenReturn(designatorEntityList);
        assertNotNull(designatorDaoImpl.saveDesignators(dto));
    }
}