iTP Secure WebServer System Administrator's Guide (iTPWebSvr 6.0+)

Using NonStop Servlets for JavaServer Pages

(NSJSP)

iTP Secure WebServer System Administrator’s Guide—523346-002

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Model-View-Controller Designs

There are two design philosophies for JSP usage. The approaches differ in terms of

where most of the processing takes place. In the first approach, shown in Figure 9-4, A

Basic NSJSP Model, the incoming request from a web browser is sent directly to the

JSP page which is responsible for processing it and replying back to the client. There

is separation of content from presentation because data access is performed using

Java beans.

This is fine for simple applications but requires all request processing to be in the JSP

page. Each page must therefore be individually responsible for managing application

state and verifying authentication and maintaining security. The second approach is to

adopt the model-view-controller design, see Figure 9-5, A Model-View-Controller

Design. In this, processing is divided between the controller and presentation

components. The presentation component, or View, are JSP pages that generate the

HTML or XML response that determines the user interface rendered by the browser.

The controller (a servlet or JSP page) is a front-end that is not concerned with

presentation, just the processing of HTTP requests. The controller instantiates beans

and other objects to be used by the presentation component.

Figure 9-4. A Basic NSJSP Model

VST904.vsd

JSP

Java Bean

or Java Servlet

REQ

RES

CLIENT

BROWSER

WEB CONT AINER

Data Storage