Is there any (GUI) tool that I can use in this way?

I start Java Application (Swing/AWT and/or JSP/servlet) and I can see which
Java object (class) was called and which method in that class was called.
And I can "travel" through this app and see how it was developed.
** I have source code.

I ask this because I need to maintain and upgrade application that was
develop by other people. Documentation was very bad and I can't figure out
how it really works.

I hope I make my problem clear!

What is the best way to do this and which tool to use for this?

Thanks.

DeTtv (DeTtv@yahoo.com) wrote:
: I start Java Application (Swing/AWT and/or JSP/servlet) and I can see which
: Java object (class) was called and which method in that class was called.
: And I can "travel" through this app and see how it was developed.
: ** I have source code.

A debugger or a profiler... 

: What is the best way to do this and which tool to use for this?
You could try JSwat Java Debugger, I havent used it myself but 
it looks ok. 

/robo