Make sure powermockito and mockito versions are aligned as in this versions chart - MockitoUsage#supported-versions,

Mockito                     | PowerMock
------------------------------------------------------------------------------
2.0.0-beta - 2.0.42-beta    |   1.6.5+
------------------------------------------------------------------------------
1.10.19                     |   1.6.4
1.10.8 - 1.10.x             |   1.6.2+
1.9.5-rc1 - 1.9.5           |   1.5.0 - 1.5.6
1.9.0-rc1 & 1.9.0           |   1.4.10 - 1.4.12
1.8.5                       |   1.3.9 - 1.4.9
1.8.4                       |   1.3.7 & 1.3.8
1.8.3                       |   1.3.6
1.8.1 & 1.8.2               |   1.3.5
1.8                         |   1.3
1.7                         |   1.2.5

Easy way to find mockito and powermock-mockito version using maven is,

mvn dependency:tree | grep mockito
[INFO] |  \- org.mockito:mockito-core:jar:1.8.5:compile
[INFO] +- org.mockito:mockito-all:jar:1.8.5:compile
[INFO] +- org.powermock:powermock-api-mockito:jar:1.4.9:compile

Problem could be the conflicting versions of mockito in the application and the one that powermockito uses, conflicting as below in my case where I'm using powermock 1.6.5 which does not support mockito 1.8.5

mvn clean dependency:tree | grep mockito
[INFO] +- org.mockito:mockito-all:jar:1.8.5:compile

[INFO] \- org.powermock:powermock-api-mockito:jar:1.6.5:compile
[INFO]    +- org.mockito:mockito-core:jar:1.10.19:compile
[INFO]    \- org.powermock:powermock-api-mockito-common:jar:1.6.5:compile

To directly answer your question, yes, you can mock some methods without mocking others. This is called a partial mock. See the Mockito documentation on partial mocks for more information.

For your example, you can do something like the following, in your test:

Stock stock = mock(Stock.class);
when(stock.getPrice()).thenReturn(100.00);    // Mock implementation
when(stock.getQuantity()).thenReturn(200);    // Mock implementation
when(stock.getValue()).thenCallRealMethod();  // Real implementation

In that case, each method implementation is mocked, unless specify thenCallRealMethod() in the when(..) clause.

There is also a possibility the other way around with spy instead of mock:

Stock stock = spy(Stock.class);
when(stock.getPrice()).thenReturn(100.00);    // Mock implementation
when(stock.getQuantity()).thenReturn(200);    // Mock implementation
// All other method call will use the real implementations

In that case, all method implementation are the real one, except if you have defined a mocked behaviour with when(..).

There is one important pitfall when you use when(Object) with spy like in the previous example. The real method will be called (because stock.getPrice() is evaluated before when(..) at runtime). This can be a problem if your method contains logic that should not be called. You can write the previous example like this:

Stock stock = spy(Stock.class);
doReturn(100.00).when(stock).getPrice();    // Mock implementation
doReturn(200).when(stock).getQuantity();    // Mock implementation
// All other method call will use the real implementations

Another possibility may be to use org.mockito.Mockito.CALLS_REAL_METHODS, such as:

Stock MOCK_STOCK = Mockito.mock( Stock.class, CALLS_REAL_METHODS );

This delegates unstubbed calls to real implementations.

However, with your example, I believe it will still fail, since the implementation of getValue() relies on quantity and price, rather than getQuantity() and getPrice(), which is what you've mocked.

Another possibility is to avoid mocks altogether:

@Test
public void getValueTest() {
    Stock stock = new Stock(100.00, 200);
    double value = stock.getValue();
    assertEquals("Stock value not correct", 100.00*200, value, .00001);
}

I got around this by upgrading to the latest version of mockito. Currently it is:

testImplementation "org.mockito:mockito-core:2.25.1"

After that I had some build errors which was resolved by selecting

File->Invalidate Caches / Restart...

I propose that you create a stub of your SomeClass that returns known values for the getProperty1() and getProperty2() method. Depending on how SomeClass is implemented, you could either create a new instance of it directly, subclass and override some methods, create an anonymous inner class if it is an interface, etc.

@Test
public void testSomething(){

    String xyz = "";
    Integer i = 10;

    // alt 1:
    SomeClass stub = new SomeClass(xyz, i);

    // alt 2: 
    SomeClass stub = new StubSomeClass(xyz, i); // StubSomeClass extends SomeClass

    // alt 3: 
    SomeClass stub = new SomeClass() {
         @Override
         String getProperty1() {
             return xyz;
         }
         @Override
         Integer getProperty2() {
             return i;
         }
    }

    Gson gson = new Gson();
    String json = gson.toJson(stub);

    this.mockmvc.perform(put("/someUrl/")
        .contentType(MediaType.APPLICATION_JSON).content(json))
        .andExpect(status().isOk());
}

Spring Test needs to know what configuration you are using (and hence where to scan for beans that it loads). To achieve what you want you have more options, the most basic ones are these two:

1. Create configuration class outside the test class that includes your bean

   @Configuration
   public class TestConfig {
   
       @Bean
       public MyService monitoringService() {
           return new MyService();
       }
   }
   

and then add it to to test as configuration class @SpringBootTest(classes = { SomeSpringConfig.class, TestConfig.class })

or

2. If you only need to use this configuration in this particular test, you can define it in static inner class

   public class SomeSpringConfigTest {
   
       @Configuration
       static class ContextConfiguration {
   
           @Bean
           public MyService monitoringService() {
               return new MyService();
           }
       }
   }
   

this will be automatically recognized and loaded by spring boot test

You don't need MockRestServiceServer object. The annotation is @InjectMocks not @Inject. Below is an example code that should work

@RunWith(MockitoJUnitRunner.class)
public class SomeServiceTest {
    @Mock
    private RestTemplate restTemplate;

    @InjectMocks
    private SomeService underTest;

    @Test
    public void testGetObjectAList() {
        ObjectA myobjectA = new ObjectA();
        //define the entity you want the exchange to return
        ResponseEntity<List<ObjectA>> myEntity = new ResponseEntity<List<ObjectA>>(HttpStatus.ACCEPTED);
        Mockito.when(restTemplate.exchange(
            Matchers.eq("/objects/get-objectA"),
            Matchers.eq(HttpMethod.POST),
            Matchers.<HttpEntity<List<ObjectA>>>any(),
            Matchers.<ParameterizedTypeReference<List<ObjectA>>>any())
        ).thenReturn(myEntity);

        List<ObjectA> res = underTest.getListofObjectsA();
        Assert.assertEquals(myobjectA, res.get(0));
    }

If you can't change the code, you can use Powermock along with junit and Mockito to mock the construction of new objects.

@Test
public void testDoWork() throws Exception{

    MyTest mytest = new MyTest();

    OtherObj obj = new OtherObj();
    obj.test="mocked Test"; //here you can add any other needed values to obj

    PowerMockito.whenNew(OtherObj.class).withNoArguments().thenReturn(obj);

    String result = mytest.doWork();
    Assert.assertTrue(result.equalsIgnoreCase("mocked Test"));
}

You can try DataFactory: Generate test data with DataFactory

Also I found this poject at google code that could be helpful: Random Data Generator

They are not equivalent to nBuilder, but they try to provide similar functionality to the one provided by nBuilder. It's not a perfect replacement but is the closer I could find.

Hope this helps.

If you want to stub out what INSTANCE returns, you can do it but it's kind of nasty (using reflection & bytecode manipulation). I created & tested a simple project with three classes using the PowerMock 1.4.12 / Mockito 1.9.0. All classes were in the same package.

SingletonObject.java

public enum SingletonObject {
    INSTANCE;
    private int num;

    protected void setNum(int num) {
        this.num = num;
    }

    public int getNum() {
        return num;
    }
}

SingletonConsumer.java

public class SingletonConsumer {
    public String consumeSingletonObject() {
        return String.valueOf(SingletonObject.INSTANCE.getNum());
    }
}

SingletonConsumerTest.java

import static org.junit.Assert.*;
import static org.powermock.api.mockito.PowerMockito.*;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import org.powermock.reflect.Whitebox;

@RunWith(PowerMockRunner.class)
@PrepareForTest({SingletonObject.class})
public class SingletonConsumerTest {
    @Test
    public void testConsumeSingletonObject() throws Exception {
        SingletonObject mockInstance = mock(SingletonObject.class);
        Whitebox.setInternalState(SingletonObject.class, "INSTANCE", mockInstance);

        when(mockInstance.getNum()).thenReturn(42);

        assertEquals("42", new SingletonConsumer().consumeSingletonObject());
    }
}

The call to the Whitebox.setInternalState replaces INSTANCE with a mock object that you can manipulate within your test.