List of Classes and Methods of org.mockito.internal.creation package of Mockito Framework

PowerMock 1.6 isn't compatible with Mockito 2.7 (take a look at https://github.com/powermock/powermock/wiki/Mockito#supported-versions)

You should use PowerMock 1.7.0RC2 (or 1.7.0RC3 if 1.7.0RC2 doesn't work), and also use powermock-api-mockito2 instead of powermock-api-mockito.

Technically speaking both "mocks" and "spies" are a special kind of "test doubles".

Mockito is unfortunately making the distinction weird.

A mock in mockito is a normal mock in other mocking frameworks (allows you to stub invocations; that is, return specific values out of method calls).

A spy in mockito is a partial mock in other mocking frameworks (part of the object will be mocked and part will use real method invocations).

The other answer is: fix your design instead of turning to the big PowerMock hammer.

Yes, PowerMock allows you to mock static methods. But you should understand: static is an abnormality in good OO design. You only use it when you have very good reasons. As it leads to tight coupling between your classes, and surprise: it breaks your ability to write reasonable unit tests. Yes, PowerMock works; but sometimes, it does not. When your classes grow, and you do more and more things "statically", because, you know, PowerMock will do the job ... be prepared for bizarre fails at some point, that can take hours to hunt down; without ever finding real bugs in your production code.

So, consider an alternative:

1. Do not use static method calls. And if there is some static method around that you can't touch; consider building a small interface around that.
2. Instead: use dependency injection and simply pass objects implementing some interface into your production code. Because you can mock such objects without the need for PowerMock(ito).

In that sense: you simply created hard to test code. Now you intend to fix that using PowerMock. The other way (much more reasonable in my eyes) is to learn how to write testable code in the first place. Here is a good starting point for that.

See Update below: You don't need a Factory

If you are using Jersey 2, one solution would be to use Custom Injection and Lifecycle Management feature (with HK2 - which comes with the Jersey dist). Also required would be a Mocking framework of course. I'm going to use Mockito.

First create a Factory with mocked instance:

public static interface GreetingService {
    public String getGreeting(String name);
}

public static class MockGreetingServiceFactory 
                                     implements Factory<GreetingService> {
    @Override
    public GreetingService provide() {
        final GreetingService mockedService
                = Mockito.mock(GreetingService.class);
        Mockito.when(mockedService.getGreeting(Mockito.anyString()))
                .thenAnswer(new Answer<String>() {
                    @Override
                    public String answer(InvocationOnMock invocation) 
                                                      throws Throwable {
                        String name = (String)invocation.getArguments()[0];
                        return "Hello " + name;
                    }

                });
        return mockedService;
    }

    @Override
    public void dispose(GreetingService t) {}
}

Then use the AbstractBinder to bind the factory to the interface/service class, and register the binder. (It's all described in the link above):

@Override
public Application configure() {
    AbstractBinder binder = new AbstractBinder() {
        @Override
        protected void configure() {
            bindFactory(MockGreetingServiceFactory.class)
                               .to(GreetingService.class);
        }
    };
    ResourceConfig config = new ResourceConfig(GreetingResource.class);
    config.register(binder);
    return config;
}

Seems like a lot, but it's just an option. I'm not too familiar with the test framework, or if it has an mocking capabilities for injection.

Here is the full test:

import javax.inject.Inject;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.client.Client;
import javax.ws.rs.client.ClientBuilder;
import javax.ws.rs.core.Application;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import org.glassfish.hk2.api.Factory;
import org.glassfish.hk2.utilities.binding.AbstractBinder;
import org.glassfish.jersey.server.ResourceConfig;
import org.glassfish.jersey.test.JerseyTest;
import org.junit.Assert;
import org.junit.Test;
import org.mockito.Mockito;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;

public class ServiceMockingTest extends JerseyTest {

    @Path("/greeting")
    public static class GreetingResource {

        @Inject
        private GreetingService greetingService;

        @GET
        @Produces(MediaType.TEXT_PLAIN)
        public String getGreeting(@QueryParam("name") String name) {
            return greetingService.getGreeting(name);
        }
    }

    public static interface GreetingService {
        public String getGreeting(String name);
    }
    
    public static class MockGreetingServiceFactory 
                                  implements Factory<GreetingService> {
        @Override
        public GreetingService provide() {
            final GreetingService mockedService
                    = Mockito.mock(GreetingService.class);
            Mockito.when(mockedService.getGreeting(Mockito.anyString()))
                    .thenAnswer(new Answer<String>() {
                        @Override
                        public String answer(InvocationOnMock invocation) 
                                                       throws Throwable {
                            String name = (String)invocation.getArguments()[0];
                            return "Hello " + name;
                        }

                    });
            return mockedService;
        }

        @Override
        public void dispose(GreetingService t) {}
    }

    @Override
    public Application configure() {
        AbstractBinder binder = new AbstractBinder() {
            @Override
            protected void configure() {
                bindFactory(MockGreetingServiceFactory.class)
                        .to(GreetingService.class);
            }
        };
        ResourceConfig config = new ResourceConfig(GreetingResource.class);
        config.register(binder);
        return config;
    }
    
    @Test
    public void testMockedGreetingService() {
        Client client = ClientBuilder.newClient();
        Response response = client.target("http://localhost:9998/greeting")
                .queryParam("name", "peeskillet")
                .request(MediaType.TEXT_PLAIN).get();
        Assert.assertEquals(200, response.getStatus());
        
        String msg = response.readEntity(String.class);
        Assert.assertEquals("Hello peeskillet", msg);
        System.out.println("Message: " + msg);
        
        response.close();
        client.close();
       
    }
}

Dependencies for this test:

<dependency>
    <groupId>org.glassfish.jersey.test-framework.providers</groupId>
    <artifactId>jersey-test-framework-provider-grizzly2</artifactId>
    <version>2.13</version>
</dependency>
<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-all</artifactId>
    <version>1.9.0</version>
</dependency>

UPDATE

So in most cases, you really don't need a Factory. You can simply bind the mock instance with its contract:

@Mock
private Service service;

@Override
public ResourceConfig configure() {
    MockitoAnnotations.initMocks(this);
    return new ResourceConfig()
        .register(MyResource.class)
        .register(new AbstractBinder() {
            @Override
            protected configure() {
                bind(service).to(Service.class);
            }
        });
}

@Test
public void test() {
    when(service.getSomething()).thenReturn("Something");
    // test
}

Much simpler!

Actually, the problem is that each verify call is made on the same spySchool instance. Let me explain:

@Test 
public void testCountPerson() {    
    School mSchool = School.getInstance();
    School spySchool = Mockito.spy(mSchool); // a spy is created here, Mockito is listening in.
    spySchool.countPerson(true); // real method is invoked
    verify(spySchool).countIncludeTeacher(); // our spy identified that countIncludeTeacher was called

    spySchool.countPerson(false); // real method is invoked
    verify(spySchool, times(0)).countIncludeTeacher(); // our spy still identified that countIncludeTeacher was called, before it was called before
}

The thing is that in the latest verify, it fails because the countIncludeTeacher method was called on the spy before and that called was not deregistered.

You can do it using verifyNoMoreInteractions, which verifies that the object had no more interactions. You could also reset the object.

But note that this is really not recommended, quoting Mockito Javadoc:

A word of warning: Some users who did a lot of classic, expect-run-verify mocking tend to use verifyNoMoreInteractions() very often, even in every test method. verifyNoMoreInteractions() is not recommended to use in every test method. verifyNoMoreInteractions() is a handy assertion from the interaction testing toolkit. Use it only when it's relevant. Abusing it leads to overspecified, less maintainable tests. You can find further reading here.

And

Smart Mockito users hardly use this feature because they know it could be a sign of poor tests. Normally, you don't need to reset your mocks, just create new mocks for each test method.

Instead of reset() please consider writing simple, small and focused test methods over lengthy, over-specified tests. First potential code smell is reset() in the middle of the test method. This probably means you're testing too much. Follow the whisper of your test methods: "Please keep us small & focused on single behavior".

I would definitely suggest that you split this test in two: one for the true case and one for the false case.

Have you installed the Spek plugin for IntelliJ?

Just search for spek in the IntelliJ plugin settings.

Best method is to use WireMock. Add the following dependencies:

    <dependency>
        <groupId>com.github.tomakehurst</groupId>
        <artifactId>wiremock</artifactId>
        <version>2.4.1</version>
    </dependency>
    <dependency>
        <groupId>org.igniterealtime.smack</groupId>
        <artifactId>smack-core</artifactId>
        <version>4.0.6</version>
    </dependency>

Define and use the wiremock as shown below

@Rule
public WireMockRule wireMockRule = new WireMockRule(8089);

String response ="Hello world";
StubMapping responseValid = stubFor(get(urlEqualTo(url)).withHeader("Content-Type", equalTo("application/json"))
            .willReturn(aResponse().withStatus(200)
                    .withHeader("Content-Type", "application/json").withBody(response)));

If you want to test using the URL, then you will need to start a server from your test. You can explicitly start an embedded server, which is pretty common for tests. Something like

public class MyResourceTest {

    public static final String BASE_URI = "http://localhost:8080/api/";
    private HttpServer server;

    @Before
    public void setUp() throws Exception {
        final ResourceConfig rc = new ResourceConfig(Service.class);
        server = GrizzlyHttpServerFactory.createHttpServer(URI.create(BASE_URI), rc);       
    }

    @After
    public void tearDown() throws Exception {
        server.stop();
    }

    @Test
    public void testService() {
        Client client = ClientBuilder.newClient();
        WebTarget target = client.target(BASE_URI).path("service");
        ...
    }
}

It's basically an integration test. You're starting the Grizzly container and loading a ResourceConfig to the server with only the Service class. Of course you could add more classes to the configuration. You can use "real" resource config if you wanted.

The above test uses this dependency

<dependency>
    <groupId>org.glassfish.jersey.containers</groupId>
    <artifactId>jersey-container-grizzly2-http</artifactId>
    <version>${jersey2.version}</version>
</dependency>

Another option, which is the one I prefer, is to make use of the Jersey Test Framework, which will start an embedded container for you. A test might look something more like

public class SimpleTest extends JerseyTest {
 
    @Override
    protected Application configure() {
        return new ResourceConfig(Service.class);
    }
 
    @Test
    public void test() {
        String hello = target("service").request().get(String.class);
    }
}

Using this dependency

<dependency>
    <groupId>org.glassfish.jersey.test-framework.providers</groupId>
    <artifactId>jersey-test-framework-provider-grizzly2</artifactId>
    <version>${jersey2.version}</version>
    <scope>test</scope>
</dependency>

And embedded Grizzly container will get started under the hood, with your ResourceConfig configuration. In both examples above it is assumed the @Path value for the Service class is service, as you can see in the test URLs.

Some Resources

• Jersey 2 Test Framework user guide

Some Examples

• How to write Unit Test for this class using Jersey 2 test framework
• How to in-memory unit test Spring-Jersey
• Example with Mockito, Test Framework, and Jersey 2
• Example with Mockito, Test Framework, and Jersey 1

UPDATE

If you're not using Maven, here are the jars you will need to run an embedded Grizzly container for the Jersey Test Fraemwork

I usually search for all my jars here. You can select the version and there should be a link in the next page, to download. You can use the search bar to search for the others.

Here's a simple running example, once you have all the jars

import com.sun.jersey.api.client.WebResource;
import com.sun.jersey.api.core.DefaultResourceConfig;
import com.sun.jersey.spi.container.servlet.WebComponent;
import com.sun.jersey.test.framework.JerseyTest;
import com.sun.jersey.test.framework.WebAppDescriptor;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import junit.framework.Assert;
import org.junit.Test;

public class SimpleTest extends JerseyTest {
    
    @Path("service")
    public static class Service {
        @GET
        public String getTest() { return "Hello World!"; }
    }

    public static class AppConfig extends DefaultResourceConfig {
        public AppConfig() {
            super(Service.class);
        }
    }
    
    @Override
    public WebAppDescriptor configure() {
        return new WebAppDescriptor.Builder()
                .initParam(WebComponent.RESOURCE_CONFIG_CLASS, 
                           AppConfig.class.getName())
                .build();
    }
    
    @Test
    public void doTest() {
        WebResource resource = resource().path("service");
        String result = resource.get(String.class);
        Assert.assertEquals("Hello World!", result);
        System.out.println(result);
    }
}

You're most likely not going to have the resources and ResourceConfig in the same class as the test, but I just want to keep it simple and all visible in one class.

Whether you are using a web.xml or a ResourceConfig subclass (as shown above), you can cut down what you test by using a separate ResourceConfig, built in the test class, as I have done. Otherwise, if you are using your normal ResourceConfig class, you can just replace it in the configure method.

The configure method, is pretty much just building a web.xml file, just in Java code. You can see different methods in the WebAppDescriptor.Builder, like initParam, which is the same as an <init-param> in your web xml. You can simply use the string in the arguments, but there are some constants, as I used above.

The @Test is you usual JUnit test that will run. It is using the Jersey Client. But instead of creating the Client, you can simply just use the preconfigured Client by just accessing the resource() method, which returns a WebResource. If you are familiar with the Jersey Client, then this class should not be new to you.

Use PowerMockito on top of Mockito.

Example code:

@RunWith(PowerMockRunner.class)
@PrepareForTest(DriverManager.class)
public class Mocker {

    @Test
    public void shouldVerifyParameters() throws Exception {

        //given
        PowerMockito.mockStatic(DriverManager.class);
        BDDMockito.given(DriverManager.getConnection(...)).willReturn(...);

        //when
        sut.execute(); // System Under Test (sut)

        //then
        PowerMockito.verifyStatic();
        DriverManager.getConnection(...);

    }

More information:

• Why doesn't Mockito mock static methods?