Javaserver Pages

JavaServer Pages
JavaServer Pages (JSP) technology is the Java platform technology for delivering dynamic content to web clients in a portable, secure and well-defined way. The JavaServer Pages specification extends the Java Servlet API to provide web application developers with a robust framework for creating dynamic web content on the server using HTML, and XML templates, and Java code, whichis secure, fast, and independent of server platforms. JSP has been built on top of the Servlet API and utilizes Servlet semantics. JSP has become the preferred request handler and response mechanism. Although JSP technology is going to be a powerful successor to basic Servlets, they have an evolutionary relationship and can be used in a cooperative and complementary manner. Servlets are powerfuland sometimes they are a bit cumbersome when it comes to generating complex HTML. Most servlets contain a little code that handles application logic and a lot more code that handles output formatting. This can make it difficult to separate and reuse portions of the code when a different output format is needed. For these reasons, web application developers turn towards JSP as their preferredservlet environment.

Evolution of Web Applications
Over the last few years, web server applications have evolved from static to dynamic applications. This evolution became necessary due to some deficiencies in earlier web site design. For example, to put more of business processes on the web, whether in business-toconsumer (B2C) or business-to-business (B2B) markets, conventional web site designtechnologies are not enough. The main issues, every developer faces when developing web applications, are: 1. Scalability - a successful site will have more users and as the number of users is increasing fastly, the web applications have to scale correspondingly. 2. Integration of data and business logic - the web is just another way to conduct business, and so it should be able to use the samemiddle-tier and data-access code. 3. Manageability - web sites just keep getting bigger and we need some viable mechanism to manage the ever-increasing content and its interaction with business systems. 4. Personalization - adding a personal touch to the web page becomes an essential factor to keep our customer coming back again. Knowing their preferences, allowing them to configure the informationthey view, remembering their past transactions or frequent search keywords are all important in providing feedback and interaction from what is otherwise a fairly one-sided conversation. Apart from these general needs for a business-oriented web site, the necessity for new technologies to create robust, dynamic and compact server-side web applications has been

realized. The main characteristicsof today's dynamic web server applications are as follows: 1. Serve HTML and XML, and stream data to the web client 2. Separate presentation, logic and data 3. Interface to databases, other Java applications, CORBA, directory and mail services 4. Make use of application server middleware to provide transactional support. 5. Track client sessions Now let us have a look on the role of Java technologyand platform in this regard.

Java's Role for Server Applications
Sun Microsystems, having consulted many expert partners from other related IT industries, has come out with a number of open APIs for the technologies and services on server side. This collection of APIs is named as Java 2 Enterprise Edition (J2EE). The J2EE specification provides a platform for enterprise applications, withfull API support for enterprise code and guarantees of portability between server implementations. Also it brings a clear division between code which deals with presentation, business logic and data. The J2EE specification meets the needs of web applications because it provides: 1. Rich interaction with a web server via servlets and built-in support for sessions available in both servlets and EJBs....