iterating active java sessions

[erjdriver]

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

 

[Manish Pandit]

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/HttpSessionListener.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

 

[erjdriver]

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]

 

[erjdriver]

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 )

 

[Manish Pandit]

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