JavaServer Pages (JSP) Overview

JSP technology offers a simple way to create dynamic web pages giving users more freedom through Java technology’s “Write Once, Run Anywhere™” capability.

JSP technology separates content generation from presentation and takes advantage of reusable tags and objects, simplifying the maintenance of web applications.  JSP technology provides users with two options:

• The scripting ability needed to create simple and interactive Web pages, or
• Scaling to support complex web sites that are fully integrated with enterprise class applications

Benefits of JSP Technology
Easier use without the need to learn the Java language.  HTML-savvy web page developers and designers can use JSP technology without the ability to write Java scriptlets.  Although scriptlets are no longer required to generate dynamic content, they are still supported to provide backward capability.

Easier to extend the JSP language.  Java technology-savvy tag library developers and designers will find it is even easier to extend the JSP language with "simple tag handlers". Simple tag handlers utilize a new, much simpler and cleaner, tag extension API. This will spur the growing number of pluggable, reusable tag libraries available, which reduces the amount of code needed to write powerful web applications.

As part of the Java family, JSP technology enables rapid development of web-based applications that are platform independent. JavaServer Pages technology separates the user interface from content generation enabling designers to change the overall page layout without altering the underlying dynamic content.

JavaServer Pages technology uses XML-like tags that encapsulate the logic that generates the content for the page.

• Vs. Active Server Pages (ASP).  ASP is a similar technology from Microsoft. The advantages of JSP are twofold. First, the dynamic part is written in Java, not Visual Basic or other MS-specific language, so it is more powerful and easier to use. Second, it is portable to other operating systems and non-Microsoft Web servers.
• Vs. Pure Servlets. JSP doesn't give you anything that you couldn't in principle do with a servlet. But it is more convenient to write (and to modify!) regular HTML than to have a zillion println statements that generate the HTML. Plus, by separating the look from the content you can put different people on different tasks: your Web page design experts can build the HTML, leaving places for your servlet programmers to insert the dynamic content.
• Vs. JavaScript. JavaScript can generate HTML dynamically on the client. This is a useful capability, but only handles situations where the dynamic information is based on the client's environment. With the exception of cookies, HTTP and form submission data is not available to JavaScript. And, since it runs on the client, JavaScript can't access server-side resources like databases, catalogs, pricing information, and the like.
• Vs. Static HTML. Regular HTML, of course, cannot contain dynamic information. JSP is so easy and convenient that it is quite feasible to augment HTML pages that only benefit marginally by the insertion of small amounts of dynamic data. Previously, the cost of using dynamic data would preclude its use in all but the most valuable instances.