Null Pointer Exception, when Writing Junit/Mockito Test cases at Controller class for Oauth, JSON response

Question

I'm relatively new to Testing in Mockito, and I'm trying to write few test cases for Controller level testing and I'm getting Null pointer Exception when I'm running the test case. I'm Injecting mocks at controller layer and mocking the service layer methods. Please let me know, the issue

Controller Class:

@RestController
@RequestMapping(value="v1.0/authentication")
public class OauthTokenController {

    //Logging
    private static final Logger LOG = LoggerFactory.getLogger(OauthTokenController.class);

    @Autowired
    private SsasServiceImpl ssasService;

    @RequestMapping(value="/oauth/token", method=RequestMethod.POST, consumes = MediaType.APPLICATION_JSON_VALUE, produces = MediaType.APPLICATION_JSON_VALUE)
    public TokenActivationResponse grantToken(@RequestParam("username") String username, @RequestParam("password") String password, @RequestParam("grant_type") String grant_type){
        TokenActivationResponse tokenActivationResponse = new TokenActivationResponse();
        SecureString passwordSecured = new SecureString(password);
        try{
            tokenActivationResponse = ssasService.grantToken(username, passwordSecured, grant_type);
            if(tokenActivationResponse == null){
                throw new Exception();
            }
            LOG.info("Printing the response " + tokenActivationResponse);
        }catch(Exception e){
            LOG.error("Exception in oauth token granting controller", e);
        }
        return tokenActivationResponse;
    }
}

SSASServiceImpl:

public class SSASServiceImpl{
    public TokenActivationResponse grantToken(String username, SecureString password, String grant_type) throws IdvException {
        MultiValueMap<String, String> body = new LinkedMultiValueMap<String, String>();
        body.add(USERNAME, username);
        body.add(PASSWORD, (password != null) ? String.valueOf(password.getContent()) : null);
        body.add(GRANT_TYPE, grant_type);
        com.idv.gateway.api.ssas.rest.client.model.TokenActivationResponse tokenResponse = new com.idv.gateway.api.ssas.rest.client.model.TokenActivationResponse();
        TokenActivationResponse response = new TokenActivationResponse();
        tokenResponse = restProxy.sendAndReceiveToRestService(body, TOKEN, HttpMethod.POST, com.idv.gateway.api.ssas.rest.client.model.TokenActivationResponse.class);
        response = transformGrantTokenResp(tokenResponse);
        return response;
    }


    public TokenActivationResponse transformGrantTokenResp(com.idv.gateway.api.ssas.rest.client.model.TokenActivationResponse response) throws IdvException {
        if (response != null) {
            TokenActivationResponse resp = new TokenActivationResponse();
            resp.getData().getAttributes().setAccess_token(response.getAccess_token());
            resp.getData().getAttributes().setToken_type(response.getToken_type());
            resp.getData().getAttributes().setExpires_in(response.getExpires_in());
            resp.getData().getAttributes().setScope(response.getScope());
            return resp;
        } else {
            IdvError error = new IdvError();
            error.setTitle("Token Error");
            throw new IdvException(error);
        }
    }
}

Test Class:

@RunWith(MockitoJUnitRunner.class)
public class OauthTokenControllerTest {

   String accessToken = "d6234595-812d-40fc-b519-2e3456543";
   Long expiresIn = 2905L;
   String userName = "abcd";
   String  password = "efghijk";
   String grant_type = "password";
   String  tokenType = "bearer";
   String  scope = "read write";

    @Mock
    SsasServiceImpl ssasService = new SsasServiceImpl();

    @InjectMocks
    OauthTokenController controller = new OauthTokenController();

    @Before
    public void setUp(){

    }

    TokenActivationResponse resp = new TokenActivationResponse();



    @Test
    public void testGrantToken() throws IdvException {
        resp.getData().getAttributes().setAccess_token(accessToken);
        resp.getData().getAttributes().setToken_type(tokenType);
        resp.getData().getAttributes().setExpires_in(expiresIn);
        resp.getData().getAttributes().setScope(scope);
        SecureString sec = new SecureString(password);
        Mockito.when(ssasService.grantToken(any(String.class),any(SecureString.class),any(String.class) )).thenReturn(resp);
        final TokenActivationResponse response = controller.grantToken(any(String.class),any(String.class),any(String.class));
        assertNotNull(response);
    }
}

Exception:

Connected to the target VM, address: '127.0.0.1:60951', transport: 'socket'
16:21:38.387 [main] ERROR com.idv.gateway.controller.OauthTokenController - Exception in oauth token granting controller
java.lang.Exception: null
    at com.idv.gateway.controller.OauthTokenController.grantToken(OauthTokenController.java:33)
    at com.idv.gateway.controller.OauthTokenControllerTest.testGrantToken(OauthTokenControllerTest.java:61)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.mockito.internal.runners.DefaultInternalRunner$1.run(DefaultInternalRunner.java:79)
    at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:85)
    at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:39)
    at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:163)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

java.lang.AssertionError
    at org.junit.Assert.fail(Assert.java:86)
    at org.junit.Assert.assertTrue(Assert.java:41)
    at org.junit.Assert.assertNotNull(Assert.java:712)
    at org.junit.Assert.assertNotNull(Assert.java:722)
    at com.idv.gateway.controller.OauthTokenControllerTest.testGrantToken(OauthTokenControllerTest.java:62)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.mockito.internal.runners.DefaultInternalRunner$1.run(DefaultInternalRunner.java:79)
    at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:85)
    at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:39)
    at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:163)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

Disconnected from the target VM, address: '127.0.0.1:60951', transport: 'socket'
[MockitoHint] OauthTokenControllerTest.testGrantToken (see javadoc for MockitoHint):
[MockitoHint] 1. Unused... -> at com.idv.gateway.controller.OauthTokenControllerTest.testGrantToken(OauthTokenControllerTest.java:60)
[MockitoHint]  ...args ok? -> at com.idv.gateway.controller.OauthTokenController.grantToken(OauthTokenController.java:31)


Process finished with exit code -1

`when(ssasService.grantToken(..).thenReturn(..)` I strongly suggest to you read some tutoruals about Mockito — dehasi, Aug 26 '18 at 20:50
@dehasi thanks, But I've tried various ways, I always get the exception at this line Controller class: tokenActivationResponse = ssasService.grantToken(username, passwordSecured, grant_type);. Still the same Null is returned by "tokenActivationResponse' — Santosh Ravi Teja, Aug 26 '18 at 20:58

score 0 · Answer 1 · answered Aug 26 '18 at 23:21

I've resolved the issue:

Solution and Fix:

In my TestCase Code, I've replaced the below any(String.class):

Mockito.when(ssasService.grantToken(any(String.class),any(SecureString.class),any(String.class) )).thenReturn(resp); final TokenActivationResponse response = controller.grantToken(any(String.class),any(String.class),any(String.class));

With (anyString()):

Mockito.when(ssasService.grantToken(anyString(),any(SecureString.class),anyString() )).thenReturn(resp); final TokenActivationResponse response = controller.grantToken(anyString(),any(String.class),anyString());

One of these Links hepled: Mockito - Invalid use of argument matchers Also, if you use argument matcher in mockito for one argument, make sure to use for all.

Null Pointer Exception, when Writing Junit/Mockito Test cases at Controller class for Oauth, JSON response

1 Answers1