Having Issues Mocking “marshalSendandReceive” method call in Mockito

Question

I'm trying to create some unit tests in Mockito, and mocking a WebServiceTemplate call that returns a JAXBElement. I continually run into a NullPointerException, along with internal Mockito errors. How do I successfully mock the method call in Mockito?

I've researched a few other problems in StackOverflow, and while some of the problems are similar, none of them have provided a successful mock and test. My tests continues to fail.

Here is the method call in my actual code, within the SearchInvoker.class.

JAXBElement<SearchResponse> response = null;
JAXBElement<SearchRequest> req = soapClient.genConn(searchReq);

try {
    response = (JAXBElement<SearchResponse>) getWebServiceTemplate().marshalSendAndReceive(req, new SoapActionCallback("search"));
} catch (RuntimeException e) {
    throw new Exception(e);
}

Here is how I'm trying to mock the call.

public class SearchInvokerTest extends PackageTest{

    @InjectMocks private SearchInvoker invoker;

    @Mock private SearchSoapClient soapClient;
    @Mock private WebServiceOperations template;

    @Test
    public void searchInvokerTest() throws Exception {
        ObjectFactory factory = new ObjectFactory();

        doReturn(factory.createSearchResponse(generateAwsSearchRsp())).when(template.marshalSendAndReceive(any(JAXBElement.class), any(WebServiceMessageCallback.class)));

        SearchResponse rsp = invoker.doSearch(new SearchRequestDVO());

        assertNotNull(rsp);
        assertEquals("123", rsp.getTraceID());
    }
}

Where I have my "when" and "doReturn" statement, I have a NullPointer as well as internal errors from Mockito. I expect the mocked class to be able to be returned.

Here is the stack trace of the error when I run mvn test:

[ERROR] Tests run: 2, Failures: 0, Errors: 2, Skipped: 0, Time elapsed: 0.018 s <<< FAILURE! - in SearchInvokerTest
[ERROR] searchInvokerTest(SearchInvokerTest)  Time elapsed: 0.002 s  <<< ERROR!
java.lang.NullPointerException
        at SearchInvokerTest.searchInvokerTest(SearchInvokerTest.java:33)

[ERROR] searchInvokerTest(SearchInvokerTest)  Time elapsed: 0.017 s  <<< ERROR!
org.mockito.exceptions.misusing.InvalidUseOfMatchersException:

Misplaced or misused argument matcher detected here:

-> at SearchInvokerTest.searchInvokerTest(SymcorSearchInvokerTest.java:33)
-> at SearchInvokerTest.searchInvokerTest(SymcorSearchInvokerTest.java:33)

You cannot use argument matchers outside of verification or stubbing.
Examples of correct usage of argument matchers:
    when(mock.get(anyInt())).thenReturn(null);
    doThrow(new RuntimeException()).when(mock).someVoidMethod(anyObject());
    verify(mock).someMethod(contains("foo"))

This message may appear after an NullPointerException if the last matcher is returning an object
like any() but the stubbed method signature expect a primitive argument, in this case,
use primitive alternatives.
    when(mock.get(any())); // bad use, will raise NPE
    when(mock.get(anyInt())); // correct usage use

Also, this error might show up because you use argument matchers with methods that cannot be mocked.
Following methods *cannot* be stubbed/verified: final/private/equals()/hashCode().
Mocking methods declared on non-public parent classes is not supported.

Answer 1

The error message indicates that your mocks are not initialized.

You have to tell JUnit to run with the Mockito runner:

[...]
@RunWith(MockitoJRunner.class)
public class SearchInvokerTest extends PackageTest {
    [...]
}

This will, among other things, initialize your mocks.