assertTrue with "instanceof" vs assertEquals

Question

I wonder why this fails:

assertEquals(Key.class, expectedKey.getClass());

and this does not:

assertTrue(expectedKey instanceof Key);

Is there a real difference between the two?

Answer 1

Because expectedKey.getClass() gives the Class object of runtime type of the expectedKey, which may be different from Key class.

However, with instanceof, even if expectedKey runtime type is some subclass of Key class, the result will be true, because an instance of subclass, is also an instanceof the super class.

Answer 2

Because expectedKey is an instance of a subclass of Key, most probably. The error message you get from the failed assertion should tell you. Read it.

"s", for example is an instance of java.lang.Object, but its class is not java.lang.Object, it's java.lang.String.