iterating active java sessions

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erjdriver - 07 Sep 2006 23:12 GMT

is there a way to iterate active servlet http sessions.

or to be notified when a session is about to
be invalided/expired etc.

it'll be run by an administrative servlet every
night to make sure database resources are
released.

thx

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Manish Pandit - 08 Sep 2006 04:18 GMT

Hi,

You can implement callbacks for your application by implementing the
methods in HttpSessionListener. You can put your notification
logic/cleanup logic in them and configure the implementation class in
your webapp's deployment descriptor.

http://tomcat.apache.org/tomcat-5.0-doc/servletapi/javax/servlet/http/HttpSessio
nListener.html

I have not come across a way to get a hold of active http sessions -
you might want to store a sessionID and related info in a database when
a session is created (using callbacks) and flag or delete the record
when it expires (again using callbacks). This will give you a handy
list of active sessions on your server, but maintaining such a db if
your website has high traffic might be tricky.

-cheers,
Manish

> is there a way to iterate active servlet http sessions.
>
[quoted text clipped - 6 lines]
>
> thx

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erjdriver - 08 Sep 2006 13:34 GMT

thanks makes sense.

when you say save the session-id...wouldn't i have to save the
session objects also somewhere. because i don't think there's
a way to retrieve the object with just the session-id.

> Hi,

> you might want to store a sessionID and related info in a database [snipped]

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erjdriver - 08 Sep 2006 15:22 GMT

here's a silly question.

i plan have an object that implements the
HttpSessionListener interface...

now who do i have notify of this object.

i.e. who.addSessionListener( my_new_obj )

Reply to this Message

Manish Pandit - 08 Sep 2006 21:30 GMT

You configure it in your web.xml in the <listener> tag. There is no
programmatic stuff involved once you've set it up (ofcourse you've to
implement the callbacks).

The container calls the implementation methods based on the event.

<listener>
<listener-class>your.fully.qualified.classname</listener-class>
</listener>

-cheers,
Manish

> here's a silly question.
>
[quoted text clipped - 4 lines]
>
> i.e. who.addSessionListener( my_new_obj )

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iterating active java sessions

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