Java Interview Questions

These questions my previous company used to ask during an interview session.

difference between abstraction & encapsulation.
difference between aggregation and composition.
what is polymorphism
difference between method overloading and method overriding.
what is dynamic class loading and static class loading
what are class variables

what is the difference between class variables and instance variables are static variables class variables.

what do know about serialization
explain collection framework hirerchy
what is the difference between arraylist and vector
what are webservices
how do u create a request for webservice
format of response from webservice
explain MVC architecture
what is the use of TAG libraries in JSP
life cycle of formbean (in struts) when it is called first time etc.
in context to struts, how do you show errors in JSP