Acceptance Test, Stub, Bridge (Abstract & Real)

[MtK]

Hello,

I've a given set of JAVA coded Acceptance Test.

all tests use some methods that need to bridged to a no-yet-coded system.

My questions are:

1. How do I create a Stub & an Abstract Bridge so that the given Acceptance Tests compile & run (but no necessary pass).
   (without touching those Acceptance Tests)
   
2. Second step would be to start implementing the needed System (not completely, just a small portion of it)
   So now, I need a Real Bridge to the coded part of the System.
   

Can someone provided some explanation on how to do this?

Maybe some step-by-step article, with images/diagrams, but better understanding.

A live Java-Code-Demo, would be GREAT... (any other language is fine as well)