Solved

•Servlet Callback method ??

Posted on 2004-08-15
3
894 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

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

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

Configure Web Service (server application) I. Configure security for Web Services methods First, we need to protect Session bean which implements the service: 1. Open EJB deployment descriptor (ejb-jar.xml) in the EJB project that contains you…
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…
This Micro Tutorial hows how you can integrate  Mac OSX to a Windows Active Directory Domain. Apple has made it easy to allow users to bind their macs to a windows domain with relative ease. The following video show how to bind OSX Mavericks to …
This Micro Tutorial demonstrates using Microsoft Excel pivot tables, how to reverse engineer competitors' marketing strategies through backlinks.

910 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

Need Help in Real-Time?

Connect with top rated Experts

25 Experts available now in Live!

Get 1:1 Help Now