1) HttpServlet is an abstract class without any methods being abstract. In my own class which extends HttpServlet I may not implement any methods. It still compiles and runs but does not do anything useful. Then what is the benefit of not directly instantiating it?
2) I have written one jsp class which sends one GET request to the above servlet. But still the above servlet class runs. But in case of POST method it gives a 405 error. So it seems besides giving error message for POST requests servlet does not give any runtime error for any request even if we don't implement any of its methods.