As I understand, REST is a Architectural pattern, where frameworks like Jersey provide out-of-the box methods to specify GET/POST/DELETE etc methods of HTTP. Servlet provides basic functionalities that takes way boilerplate code to handle networking requests.
My question here is that even HttpServlet provides 'do' methods like doGet, doPost and one can also specifiy the path/headers etc. So exposing a webservice via HttpServlet's doGet/doPost adheres to being a RESTful webservice?