Question

For example, I have the following code:

SomeClass stub = Mockito.mock(SomeClass.class);

After that, stub is a normal implementation of SomeClass, but with its own behavior (default is to just throw some exception, but that’s ok)

How can I do the same thing for my library? I would like to be able to wrap some classes, or even better instances with some wrap() method, to mix-in my behavior there.

Answer 1

Both jmock and Mockito (which uses jmock code) use cglib internally to create their stubs/proxies. See ClassImposterizer.

For simple cases, you can use Java’s Proxy mechanism to create dynamic proxies (really just invocation handlers) of interfaces you want to stub or mock.