Question on servlet

[preethib]

Since A Java servlet is implemented within a Java class. What requirements are imposed on this class?

 

[wushutwist]

A Servlet is just a Java class that does one of three things:
1) Implements the javax.servlet.Servlet Interface.
2) Extends from javax.servlet.GenericServlet
3) Extends from javax.servlet.HttpServlet

Futhermore (straight from JavaDocs):

A subclass of HttpServlet must override at least one method, usually one of these:

· doGet, if the servlet supports HTTP GET requests 
· doPost, for HTTP POST requests 
· doPut, for HTTP PUT requests 
· doDelete, for HTTP DELETE requests 
· init and destroy, to manage resources that are held for the life of the servlet 
· getServletInfo, which the servlet uses to provide information about itself

That's it. You should probably know that 99.9% of all Servlets take the third option and extend from javax.servlet.HttpServlet. It is important to note that a Servlet doesn't have to serve HTTP Requests though, by extending from GenericServlet you could create a Servlet to handle FTP, SMTP, whatever.

 

[preethib]

Thanks! wushutwist

 

[da21]

Hi ,

I am new to servlets.I will be extremely greatfull if wushutuvist or somebody can guide me through. I have written a simple servlet HelloServlet.java and compiled it getting HelloServlet.class file. But to execute this what am i supposed to do at the localhost.What changes are needed in the Web.xml file for servlet mapping etc.
thanks

Da21