Find a copy of Head First Java (2nd edition) by Kathy Sierra and Bert Bates. Go through the chapter starting on page 235. See, all there, nice and easy to understand.
Find a copy of the Java Language Specification, and I think you want §12.4 or §12.5. See, all there, really difficult to understand.
I’ve looked at a lot of different solutions, and in my humble opinion Aspose is the way to go. Here’s the link: http://aspose.com
subject: what really happens when an extended class object is created ?