如何为CDI编写Junit测试用例？

Question

I want to write test cases for cdi. I used @inject in my dao. Can any one help me how to write test cases for cdi.I tried the below code. But its not working. Please help me.

public class StudentTest {

    StudentService stuService;

    StudentDAO stuDAO;

    StudentVO stuVo;

    @Before
    public void setUp() throws Exception {

        System.out.println("In Setup");

        stuVo=new StudentVO ();

        stuService=new StudentService();

        stuDAO=Mockito.mock(StudentDAO.class);

        stuVo.setStudId("123");

        stuVo.setName("user1");

        Mockito.when(stuDAO.getStudent(stuVo.getStuId())).thenReturn(student);
    }

    @Test
    public void getStudent() throws DataAccessException {

        StudentVO stVO=stuService.getStudent(123);

        Assert.assertEquals("123", stVO.getStuId());
    }
}

My Service Class is

public class StudentService {

    @Inject
    StudentDAO stuDao;

    public StudentVo getStudent(String id){

        return stuDao.getStudent(id);

    }

}

In failure trace its just showing as "java.lang.NullPointerException

 at com.stu.StudentService.getStudent(StudentService.java:104)
 at com.stu.junit.POCJunit.getgetStudent(StudentTest.java:21)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
 at java.lang.reflect.Method.invoke(Method.java:606)
 at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
 at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
 at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
 at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
 at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
 at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)...

Answer 1

I resolved it by putting following code

@Mock
StudentDAO stuDAO;

@InjectMocks
StudentService stuService;

And in setUp() method I have written

MockitoAnnotations.initMocks(this);

Answer 2

You are never setting the dao mock in your service bean. No injection framework is present, so the dao just remains "null" and the test fails. You could either set the dao mock directly, since you made the field package visible, or use reflection.

My preferred way: Have a look at http://www.needle4j.org/ . Its a container agnostic test framework aiming to simplify testing of DI.

Basic rule: whenever you inject something, needle4j will create a mock instance for you.