MissingMethodInvocationException is RuntimeException and subclass of MockitoException. It generally throws when:

1. It might occurs when() requires an argument which has to be ‘a method call on a mock. For example:                when(mock.getArticles()).thenReturn(articles);
2. You try to stubbed/verified either of: final/private/equals()/hashCode() methods.
3. Mocking methods declared on non-public parent classes is not supported.
4. Inside when() you don’t call method on real object always call from mock or spy.

Constructors

• MissingMethodInvocationException(String message) : Will throw exception with message.

Example

To complete example follow link Mockito + JUnit Tutorial

import static org.mockito.Mockito.spy;

import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;

import static org.mockito.Mockito.*;
//@RunWith attaches a runner with the test class to initialize the test data
@RunWith(org.mockito.runners.MockitoJUnitRunner.class)
public class MathApplicationTestrSpy {
private CalculatorService calcService;

@Before
public void setUp(){
Calculator calculator = new Calculator();
calcService = spy(calculator);
//Issue is here because using actual object
when(calculator.add(20.0,10.0)).thenReturn(30.0);
}

@Test
public void testAdd(){
Assert.assertEquals(calcService.add(20.0, 10.0),30.0,0);
}

}

Output

org.mockito.exceptions.misusing.MissingMethodInvocationException:
when() requires an argument which has to be 'a method call on a mock'.
For example:
when(mock.getArticles()).thenReturn(articles);

Also, this error might show up because:
1. you stub either of: final/private/equals()/hashCode() methods.
Those methods *cannot* be stubbed/verified.
Mocking methods declared on non-public parent classes is not supported.
2. inside when() you don't call method on mock but on some other object.

at com.facingissuesonit.mockito.MockitoTestExamples.MathApplicationTestrSpy.setUp(MathApplicationTestrSpy.java:29)
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:497)
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)

Solutions

Here in above example trying stub on real object instead of mock and spy object. To solve this issue update code as below. For complete example please refer Mockito + JUnit TutorialMockito + JUnit Tutorial.

@Before
public void setUp(){
Calculator calculator = new Calculator();
calcService = spy(calculator);
//Issue is here because using actual object
//when(calcService.add(20.0,10.0)).thenReturn(30.0);

//Used Spy object
when(calculator.add(20.0,10.0)).thenReturn(30.0);
}

References

https://static.javadoc.io/org.mockito/mockito-core/2.6.5/org/mockito/exceptions/misusing/MissingMethodInvocationException.html

Know More

To know more about Junit, Mockito and exception solutions follow below links:

• Mockito +JUnit Tutorial
• Junit Tutorial
• Mockito Exceptions