Re: Testing for a User in a Session (JSP/Servlet)

Lew <>
Wed, 21 Feb 2007 16:57:37 -0500
llama64 wrote:

Thanks Lew!

I'm "sorta" following the MVC as much as possible, but I'm still in
the process of learning all of this Java technology.

If I understand you correctly:
- initial request comes in, a servlet is given the request first
(rather then a index.html/jsp file).
- The servlet then checks the conditions I need (user is logged in),
and forwards the request to the proper page.

All requests get intercepted by a servlet to make decisions. Am I on
the right track?


There was an article in JavaPro Online (not the print edition) entitled "Who
Needs Struts?" that I wrote a year or two ago. I don't know if you can still
find it on there, but it might help get you started. (It might require a free
(as in beer) signup first.)

Typically there is a single controller servlet that mediates all requests. It
will parse out enough of the request parameters to figure out which business
logic class (usefully, a JavaBean) to invoke, then it passes the request to
the logic. Based on a result code it then selects a new JSP to display, one
which might be able to refer to the logic bean or values that it generated.
That is how results get to show up in the next screen.

It's a little like Swing, where JTable is the visual display component for a
TableModel, which is a non-visual data object.

There are variation on this idea. Wikipedia, Sun and Google are good places to
research it, and Struts is a decent framework if your project is large enough
to justify it.

- Lew

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