Mockito has a very nice feature that allows you to verify what parameters were used when a method was executed. For example:

ArgumentCaptor argument = ArgumentCaptor.forClass(Person.class);
verify(mock).doSomething(argument.capture());
assertEquals("John", argument.getValue().getName()); 

However, when using generic typed objects, some problems rise up. For example, the following won't work:

ArgumentCaptor\> argument = ArgumentCaptor.forClass(List.class); 

This is obviously not a Mockito problem, but a generics problem. To solve this, follow these two steps:

1. use the @Captor annotation.

   @Captor
   private ArgumentCaptor\> argumentCaptor; 
   

2. initialize the Mockito annotations in your initialization method (add one if you don't have one)

   @Before
   public void init(){
      MockitoAnnotations.initMocks(this);
   }
   

And presto! You can now capture the parameters that were used when a to be verified method was executed.

verify(someMock).someMethod(argumentCaptor.capture());