Re: Know the runtime class

> Is there any way to know the instance of the object of A in the class C?
> Which API method should I use for this?

Don't whether I understand you question, but java.lang.Object.getClass
takes no arguments and returns the class descriptor, i.e. an object
belonging to java.lang.Class, associated with the object on which this
method is invoked.

A side-note; Have you thought of the problems you are about to run into
considering local variables.. I mean fields can be accessed easily and
utilizing the java.lang.reflection and getClass can be used to find out
the runtime class of a value, but object references that are somewhere
on the operand stack; dynamic checks that (un)wind the stack? Problems
assure that you don't generate checks that operate on unitialized
objects..  

Have fun..