HttpServlet is an abstract class without any abstract method because the web container manufacturer restricts developer to create an object of it by declaring it abstract.
Web container should call doGet() and doPost() and it should handle all the life cycle of Servlet.
If we are allowed to create an object of HttpServlet, we are restricting container to call doGet() and doPost(), but that is the job of container itself, it should handle all the life cycle of Servlet.
So, that is why, we should not create an object of HttpServlet, so that is why it is marked abstract class without it having any abstract method.
