a heart-beat would do it. if, after x seconds, you don't receive a
heartbeat from your applet you can assume either (a) insanely heavy network
traffic, (b) client machine is unbelievably bogged down to a point where the
applet can't get a time slice, or (c) the client machine is dead and/or
disconnected from the network. combine that with simple ping and you can
even determine the difference between the browser being off and the computer
being off (again, assuming a stable, non-flooded network). (the other way,
even without power failures, is to terminate the browser process directly).
................ron.
-----Original Message-----
From: Chris Pratt <[EMAIL PROTECTED]>
To: [EMAIL PROTECTED] <[EMAIL PROTECTED]>
Date: Friday, December 03, 1999 8:33 PM
Subject: Re: [Session tracking]
>This still doesn't catch power failures. So, I guess there is really no
>sure way.
> (*Chris*)
>
>----- Original Message -----
>From: "Ted Neward" <[EMAIL PROTECTED]>
>To: <[EMAIL PROTECTED]>
>Sent: Friday, December 03, 1999 8:14 PM
>Subject: Re: [Session tracking]
>
>
>> You *can* get guaranteed notification by placing a non-visible applet on
>> the page that opens a socket back to the server, and fires a message down
>> the socket on closing; the HTML browsers are required to call the
applet's
>> "stop" method when it terminates for any reason, either leaving the page
>> or closing the browser.
>>
>> Unless somebody knows better re: the "browser-applet" specification....
>>
>> Ted Neward
>> http://www.javageeks.com/~tneward
>>
>>
>> On Fri, 3 Dec 1999, Thor HW wrote:
>>
>> > You cannot tell when the browser closes, there are many hacks, but none
>are
>> > foolproof.
>> > If you maintain a session object (your own, with state info) and if
they
>> > need to identify themselves somehow, you can restart an old session, or
>> > invalidate it.
>> > If you are tracking anonymous users, you are out of luck. You could
try
>and
>> > set a long lived cookie, but they might have cookies off, which is a
>default
>> > for AOL users.
>> >
>> > Thor HW
>> > ----- Original Message -----
>> > From: kavitha ramasamy <[EMAIL PROTECTED]>
>> > To: <[EMAIL PROTECTED]>
>> > Sent: Friday, December 03, 1999 12:23 PM
>> > Subject: Re: [Session tracking]
>> >
>> >
>> > > The value unBound is called only at two places
>> > > 1)when I am reloading the same session
>> > > 2)when the session expires.
>> > >
>> > > My problem is if the user closed the browser window , I need to
>release
>> > the
>> > > resource relevant to that session which I created at the time of
>opening.
>> > >
>> > > I cannot even invalidate my previous session because the intention of
>this
>> > > work is to prevent multisession on the same user.
>> > > If the user had a session, he cannot opened the next session.so the
>> > resource
>> > > should be released once the browser closed(clint exit)
>> > >
>> > > Thanks and Regards
>> > > kavitha
>> > >
>> > >
>> > > >
>> > > >Make your session resource class "implements
>HttpSessionBindingListener"
>> > > >
>> > > >and have the valueUnbound do your cleanup.
>> > > > public void valueUnbound (HttpSessionBindingEvent event){
>> > > > // Clean up everything in this session
>> > > > // save or rollback changes, etc.
>> > > > destroy();
>> > > > }
>> > > >
>> > > >You can read the Javadoc on HttpSessionBindingListener for details.
>> > > >
>> > > >Thor HW
>> > > >
>> > > >----- Original Message -----
>> > > >From: Pankaj <[EMAIL PROTECTED]>
>> > > >To: <[EMAIL PROTECTED]>
>> > > >Sent: Friday, December 03, 1999 8:41 AM
>> > > >Subject: Re: [Session tracking]
>> > > >
>> > > >
>> > > > > kavitha ,
>> > > > >
>> > > > > if you search the list archives for last month you will find out
a
>> > long
>> > > > > discussion of this same problem which states under the subject
>> > "Browser
>> > > > > shutdown..." that there is no guaranteed way of knowing that
>client is
>> > > >no
>> > > >more
>> > > > > interested in using your site. Please search the archives for the
>> > same.
>> > > > >
>> > > > > Pankaj.
>> > > > >
>> > > > > kavitha ramasamy <[EMAIL PROTECTED]> wrote:
>> > > > > Hi,
>> > > > >
>> > > > > I am designing that user login system, where same user cannot
>make
>> > > > > multiple sessions(multiple entries with the same name). When a
>> > > >particular
>> > > > > user is making a session, the user information is logged into the
>> > table
>> > > >and
>> > > > > released from the tablewhen the user closed the session.
>> > > > >
>> > > > > Here if the user close the system(prpoer logout of the
>system),then it
>> > > >is
>> > > > > releasing all resources,woking fine.
>> > > > >
>> > > > > Once the user made the session, if he close the browser
window(not
>> > > >proper
>> > > > > logout), I need to release the resources (session is still there)
>> > before
>> > > > > session time out.
>> > > > >
>> > > > > How can I release the resources if the user closes the browser
>window
>> > > > > before the session time out.
>> > > > >
>> > > > > Any help will be greatly appreciated
>> > > > > Thanks
>> > > > > kavitha
>> > > > >
>> > > > >
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