John Justin's blog

 In Mockito, you can mock void methods by using the "doAnswer()" method from the "org.mockito.stubbing.Answer" class. This method allows you to specify a custom implementation for a void method that will be executed when the method is called on a mock.

Here is an example of how to mock a void method using the "doAnswer()" method in Java:

import static org.mockito.Mockito.*;

import org.mockito.stubbing.Answer;

// Create a mock object

MyClass myClass = mock(MyClass.class);

// Use doAnswer to specify a custom implementation for the void method

doAnswer(new Answer<Void>() {

    public Void answer(InvocationOnMock invocation) {

        Object[] args = invocation.getArguments();

        // Perform custom logic here with the arguments passed to the method

        System.out.println("Method called with arguments: " + Arrays.toString(args));

        return null;

    }

}).when(myClass).myVoidMethod(anyInt(), anyString());

// Call the void method on the mock object

myClass.myVoidMethod(123, "hello");

// Verify that the void method was called on the mock object

verify(myClass).myVoidMethod(123, "hello");