Answer: Servlet is a server side programming language Which takes request in form of Http and gives response in the form of Http.
Answer: Servlet Interface is the central abstraction. All servlets implements this Servlet Interface either direclty or indirectly ( may implement or extend Servlet Interfaces sub classes or sub interfaces)
HttpServlet ( Class ) -- we will extend this class to handle GET / PUT HTTP requests
Answer: GenericServlet has a service() method to handle requests.HttpServlet extends GenericServlet added new methods
- doTrace() methods
Both these classes are abstract.
Answer: Servlets executes on Servers. Applets executes on browser. Unlike applets, however, servlets have no graphical user interface.
Answer: A servlet can handle multiple requests concurrently, and can synchronize requests. Servlets can forward requests to other servers and servlets. Thus servlets can be used to balance load among several servers.
Answer: When we specified method='GET' in HTML
< form name='SSS' method='GET'>
Answer: When we specified method='POST' in HTML
< form name='SSS' method='POST' >
GET Method Using get method we can able to pass 2K data from HTML All data we are passing to Server will be displayed in URL (request string).This is used to sent small size data.
POST Method: In this method we does not have any size limitation. All data passed to server will be hidden, User cannot able to see this info on the browser. .The data is send into a small packets. This used to sent large amount of data.
Answer: When first request came in for the servlet , Server will invoke init() method of the servlet. There after if any user request the servlet program, Server will directly executes the service() method. When Server want to remove the servlet from pool, then it will execute the destroy() method. The init() and destroy() methods are called at only one time. But service() method can call at each request. The service() method creates a separate thread for each request and gives response according to request.
setContentType()method must be set.