1) What are the major advantages of preferring Struts 2 over the Struts 1? What are all the advantages in Struts 1?
2) What is the use of having filter dispatcher in Struts 2?
3) Is it good to use filter dispatcher over servlet(Struts 1 uses servlet)?
As i am new to Struts can anyone give an elaborated description for these questions?
You can find Pros and Cons comparing Struts 1 and Struts 2.
To add to these features I'd say that Struts 2 not only bigger but heavier than Struts 1. Struts 2 in the default configuration intercepts and runs a lot of stuff to simplify the development process, write less code, use recent technologies, but the cost for it is a complexity of framework. You will have more time to learn a framework itself to be able to modify it to suit your needs.