Hi Prabhat,
of course you don't have to override theses methods but then your web application will be quite useless
If you plan to handle user requests (which is what you usually want when you write an application) then you simply have to override all of the methods for the corresponding HTTP methods you want to handle (GET, POST, HEAD, ...). If you don't override them your application will do nothing! The methods like doGet(), doPost() and so on is where you have to place the logic for your application. At least this is the starting point to process user requests and to generate corresponding responses for the user.
Or did you really think you don't have to write any code and your application knows what to do itself?
Marco
[ April 02, 2008: Message edited by: Marco Ehrentreich ]