Solved

•Servlet Callback method ??

Posted on 2004-08-15
3
903 Views
Last Modified: 2013-12-10
•why we say that the followings are Servlet Callback method ?
–doGet
–doPost
–Init
–Destroy

why we use the word "callback".

thanks
0
Comment
Question by:she1
3 Comments
 
LVL 23

Expert Comment

by:rama_krishna580
ID: 11807028
Hi,

A callback method is a method intended to be passed as a parameter. The callee can then call the passed method asynchronously and with whatever parameters it deems appropriate. Callbacks are often used in event handling code.

R.K
0
 
LVL 7

Expert Comment

by:damonf
ID: 11825012
as RK says, a callback method is designed to be called asynchronously.  That is, if object A owns method callback(), and object A enlists object B to perform some work, object B may later call a.callback() with the result of the work.  Object A does not need to maintain a reference to B for this to happen.

doGet and doPost are callbacks because any HTTP client can call them any time.  Init() and destroy() are callbacks because the container can call them anytime if it wishes to start and stop the servlet.  Actually doGet and doPost are really called by the container as well (in reaction to the client's HTTP request).  But they still can be called any time.
0
 
LVL 1

Accepted Solution

by:
fschutte earned 30 total points
ID: 11907693
they are simply callback methods because they are invoked by the container (every container managed component has callback methods because that's the way to communicate with the container)
0

Featured Post

ScreenConnect 6.0 Free Trial

Discover new time-saving features in one game-changing release, ScreenConnect 6.0, based on partner feedback. New features include a redesigned UI, app configurations and chat acknowledgement to improve customer engagement!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
JDBC error in Apache tomcat 6 251
WEBLOGIC 10.3.6 deployment Issue : Unable to deploy EJBs 22 294
Weblogic Logs 4 146
V.simple question about Android packages and libraries 1 21
This exercise is about for the following scenario: Dmgr and One node with 2 application server. Each application server contains it owns application. Application server name as follows server1 contains app1 server2 contains app1 Prereq…
There are numerous questions about how to setup an IBM HTTP Server to be administered from WebSphere Application Server administrative console. I do hope this article will wrap things up and become a reference for this task. You need three things…
Although Jacob Bernoulli (1654-1705) has been credited as the creator of "Binomial Distribution Table", Gottfried Leibniz (1646-1716) did his dissertation on the subject in 1666; Leibniz you may recall is the co-inventor of "Calculus" and beat Isaac…
Finds all prime numbers in a range requested and places them in a public primes() array. I've demostrated a template size of 30 (2 * 3 * 5) but larger templates can be built such 210  (2 * 3 * 5 * 7) or 2310  (2 * 3 * 5 * 7 * 11). The larger templa…

810 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question