What is Java Server Pages (JSP) Technology

Java Server Pages (JSP) technology enables Web developers and designers to rapidly develop and easily maintain, information-rich, dynamic Web pages that leverage existing business systems. As part of the Java technology family, JSP technology enables rapid development of Web-based applications that are platform-independent. JSP technology separates the user interface from content generation, enabling designers to change the overall page layout without altering the underlying dynamic content. 

Typically, a JSP page is a text-based document that contains two types of text:

• Static data, which can be expressed in any text-based format, such as HTML, Wireless Markup Language (WML), or XML
• JSP technology elements, determine how the page constructs dynamic content

Benefits for Developers:

If you are a Web page developer or designer who is familiar with HTML, you can:

• Use JSP technology without having to learn the Java language: You can use JSP technology without learning how to write Java scriplets. Although script lets are no longer required to generate dynamic content, they are still supported to provide backward compatibility.
• Extend the JSP language: Java tag library developers and designers can extend the JSP language with "simple tag handlers," which utilize a new, much simpler, and cleaner, tag extension API. This spurs the growing number of pluggable, reusable tag libraries available, which in turn reduces the amount of code needed to write powerful Web applications.
• Easily write and maintain pages: The Java Server Pages Standard Tag Library (JSTL) expression language is now integrated into JSP technology and has been upgraded to support functions. The expression language can now be used instead of script let expressions.

The packages involved in creating JSP pages are javax.el, javax.servlet.jsp, javax.servlet.jsp.el, and javax.servlet.jsp.tagext, though you will rarely have to import these directly. A JSP page can be as simple as a bit of HTML with one snippet of JSP code and the .jsp extension of the page name.

For instance, you can create a web site of JSP technology pages that use one snippet of code to include the header.html file, which contains the site navigation. This way, when you change a link to a button in the navigation, you make the change in only one file, and that file loads into all the pages on the site that have this code snippet:

<%@ include file="header.html" %>

That line of code works very much like a server-side include, if you are familiar with those. Because this web page is now a JSP page, you could also go on to add more Java technology code to create dynamic web content, such as polls, forms, ways to enter or retrieve data from a database, and so forth.