I was reading a book on servlets, in that book a brief explanation is given about the servlet class, as well as the HttpServlet class.
There is one example for filling in a form- for that form, the servlet's doPost() method is overridden by the class. But for another example of a login form, the service() method is overridden instead.
I want to know why the 2 different approaches- I thought that usually we put our custom code into doPost() (or doGet()) and let service() remain as it is. Is there any reason behind using either one of the 2 approaches, or can I use both approaches in any situation?