What is the difference between GenericServlet and HttpServlet?

GenericServlet belongs to javax.servlet package 
GenericServlet is an abstract class which extends Object and implements Servlet, ServletConfig and java.io.Serializable interfaces. 
The direct subclass to GenericServlet is HttpServlet.It is a protocol-independent servlet.  
To write a GenericServlet you need abstract service() to be overridden. 
 
 
HttpServlet: 
HttpServlet belongs to javax.servlet.http package 
This is an abstract class which extends GenericServlet and implements java.io.Serializable 
A subclass of HttpServlet must override at least one method of doGet(), doPost(),doPut(), doDelete(), init(), destroy(), getServletInfo()

Generic servlets works for every protocal and Http servlet works for only Http protocol.

GenericServlet is an abstract class it can handle all types of protocols,but HttpServlet handle only Http specific protocols.In generic we use only service method but Http we use doGet() & doPost().but now a days we use only Http becoz WWW depends upon Http PROTOCOLS.

HttpServlet is a protocol dependent whereas GenericServlet is protocol independent

Basically they 2 differences between GET and POST.

1. In GET method the information is sent through URL and it is visible to everyone where as in POST method the information is sent through the Headers which cant be visible to others.

2. Through GET method we can sent only 2KB of information(coz it will go through URL) where as with POST method we can send unlimited data as the information will be sent through Headers.

3. Generally GET method is used to get the data from the resources and POST method is used to post or store the data into DB.

when u invoked a servlet..by typing the name in the addresbar.of the internet expl..it is invoked via post method...but when u invoke it viz form button it is invoked via get method

GenericServlets are ment for generic use, where as HttpServelets are specific to Http Protocol only

The servlet that gets invoked with Common Gateway Interface protocool is known has Genaric Servlet. Limitation: Request Replication.The servlet that is invoked by HTTP protocal is know as HTTP Servlet.Advantage: It don't replicate the request.

The servlet that gets invoked with Common Gateway Interface protocool is known has Genaric Servlet. Limitation: Request Replication.The servlet that is invoked by HTTP protocal is know as HTTP Servlet.Advantage: It don't replicate the request.

1.generic srevlet for universalprotocols where as http for http protocols.

2.in generic servlet we have to implement the service method where as in http no need to implement service method.

Generic Servlet is an abstract class provided by javasoft which is designed in such away that it is not specific to a particular protocol whereas when it comes to HTTPServlet it is designed by javasoft and it is an abstractclass and it is especially designed to deal with HTTP protocols.

1. Generic Servlet are protocol independent but Http Servlet are protocol dependent.

2. Generic Servlet can handles all type of protocols but Http Servlet can handle onlyhttp specific protocols.

3.In Generic Servlet we have to implement the service method where as in http Sevlet no need to implement service method.

HttpServlet is a specific case/implementation of GenericServlet.


Thanks,
Vinay

GenericServlet is superclass to HTTPServlet.
HTTPServlet uses protocols such as get,post.

Genericservlet is protocol independent, httpservlet is protocol dependent

Genericservlet contains p v service(-,-),
httpservlet contains p v service(-,-), protected v service(-,-), doGet(-,), doPost(-,-), doPut(-,-),--------etc

httpservlet is one of the predefined subclass of genericservlet

GenericServlet suppports only service(). It handles simple requests, It is platform-independent. It handles all types of protocols like http, smtp, ftp.

HttpServlet supports both doget() & dopost(). It supports state programming also. It is platform-dependent. It handles only Http protocol.