Re: connection pooling with servlets

Thanks. I posted some of the relevant code here;

http://saloon.javaranch.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic&f=7&t=016798

But I'm still baffled as to how to get access to a session in a servlet that was called by a jsp. Should servlets have access to sessions easily? Everyone is making it seem like this shouldn't be a problem, but then I've read in other places that a jsp calling a servlet clears whatever attributes were part of the request object.

David Durham <ddurham(at)vailsys(dot)com> wrote: J. wrote:
> Thanks for replying. I'm not sure if that would help, but maybe if I
> understand the suggestion better it will.
>
> Right now I've got the index.jsp calling Login servlet via POST. Then
> Login creates the connection, puts it into a session with some other
> attributes and forward(req,res) to welcome.jsp.

Not much point in storing a datasource as a session attribute (1 datasource per application user?). More appropriate to make it application-wide by putting a datasource in a servlet context or, as someone else suggested, a static attribute/property/member/variable ... request.getSession().getServletContext().setAttribute(...). JNDI is another good place to put this sort of thing. An easy way to make sure your datasource is always available is to use a servlet context listener to create it when the application is initialized. Google for servlet context lifecycle should tell you how to do setup a listener.

Now, as for a null pointer on your connection object, maybe you have something misconfigured in your datasource. Username, password, host, and driver class are usual suspects.

> Welcome.jsp has a form
> that uses GET to call a Search servlet and this is where I get a null
> pointer on the connection object. I'm trying to get the session out of
> the request object, but it seems like the request loses state by the
> time I'm getting to it (in Search servlet).

Not sure. You can post your code and maybe get some help. Wait, is this homework?

-Dave

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