18/02/25
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Q)What are the most frequently used HTTP request methods?
     1)GET
     2)POST
Q)When are GET and POST used?

=>to get data from the database without affecting data in the database,
we go for  GET request.
        For eg. Viewing result (GET)
	Note:- secured information like   user names and paswords,
	CREDIT card numbers etc.involved we should not use GET
	even though  READ operation is performed on the database.	            
=>Whenever DML oeprations are involved  we go for POST.

Q)What is the hierarchy of servlets?

DIAGRAM

Note:- Always a user defined servlet should inherit from HttpServlet.


Q)Which is the servicing method of a realtime servlet?
=>doGet()  or doPost()

For eg.
public class  MyServlet extends HttpServlet{
   public void doGet/doPost(HttpServletRequest request,HttpServletResponse response)
   {
        //duties of a servlet
   }
}

Q)Can Servlet Container  call doGet/doPost()  ?
=>No. Can't call as they are not life cycle methods.

Q)When is doGet() called?
    =>When HTTP request method is GET type.


Q)When is doPost() called?
    =>When HTTP request method is POST type.

Q)How are protocols classified?
       1)stateless protocol
       2)stateful protocol
=>If server has got no memory of prior connections, the protocol is said to be
stateless. If it has, it is stateful.
=>FTP(File Transfer Protocol) is a stateful protocol.
=>HTTP is a stateless protocol.

Note:- HTTP provides better performance but poses some challenges to the 
web application developers as user interaction with the website should be stateful.