I have a final class, something like this:
public final class RainOnTrees{
public void startRain(){
// some code here
}
}
I
As others have stated, this won't work out of the box with Mockito. I would suggest using reflection to set the specific fields on the object that is being used by the code under test. If you find yourself doing this a lot, you can wrap this functionality in a library.
As an aside, if you are the one marking classes final, stop doing that. I ran across this question because I am working with an API where everything was marked final to prevent my legitimate need for extension (mocking), and I wish that the developer had not assumed that I would never need to extend the class.