JSP (Java server page)

 

JSP (Java server page)

 

Why java server pages?

Java server pages(JSP) technology enables you to mix regular, static HTML with dynamically generated content from servlets. Many Web pages that are built by CGI programs are primarily static , with the parts that change limited to few small locations.

For example, the initial page at most online stores is the same for all visitors, except for a small welcome message giving the visitor’s name if it is known . But most CGI variations, including servlets, make you generate the entire page via your program, even though most of it is always the same. JSP lets you create the two parts separately. Listing an example. Most of the page consists of regular HTML, which is passed to the visitor unchanged. Parts that are generated dynamically are marked with special HTML like tags and mixed right into the page.

 

The JavaServer Pages technology offers a number of advantages:

ü Write once , Run Anywhere properties

The Java server Pages technology is platform independent, both in its dynamic web pages, its web servers, and its underlying server components. You can author JSP pages on any platform, run them on any Web server or Web enabled application server  , and access them from any web browser.You can also build the server components on any platform and run them on any server.

 

ü High Quality tool support

The write once , run anywhere properties of JSP allows the user to choose best of breed tools. Additionally , an explicit goal of the java server pages design is to enable the creation of high quality portable tools.

 

ü Reuse of components and tag libraries

The java server pages technology emphasizes the use of reusable components such as : JavaBeans components, Enterprises JavaBean components and tag libraries. These components can be used in interactive tools for component development and page composition. This saves considerable development time while giving the cross-platform power and flexibility of the java programming language and other scripting languages.

 

ü Separation of dynamic and static content

The Java server pages technology enables the separation of static content from dynamic content that is inserted into the static template. This greatly simplifies the creation of content.This separation is supported by beans specifically designed for the interaction with server-side objects and specially by the tag extension mechanism.

 

ü Supporting for scripting and actions

The java server pages technology supports scripting elements as well as actions. Actions permit the encapsulation of useful functionality in a convenient form that can also be manipulated by tools; Scripts provide a mechanism to glue together this functionality in a per-page manner.

 

ü Web access layer for N-tier enterprise application architecture(s)

The Java server pages technology is an integral part of the java 2 platform enterprises edition (J2EE), which brings java technology to enterprises computing. You can now develop powerful middle-tier server applications, using a website that uses JavaServer Pages technology as a front end to Enterprise JavaBeans components in a J2EE compliant environment.

 

What is a JSP Page?

A JSP Page is a text-based document that describes how to process a request to create a response. The description intermixes template data with some dynamic actions and leverages on the Java Platform. The features in the JSP technology support a number of different paradigms for authoring of dynamic content; some of them are described in the next couple of examples only attempt to present the technical components of the JSP specification and are not prescribing “good” or “bad” paradigms.