What Are the Benefits?

Many of the first web applications were developed using the Common Gateway Interface (CGI) and scripting languages to create dynamic pages. While this worked, it was very inefficient as every request spawned a process to handle the request. Using CGI scripts also often led to security risks. JSPs alleviate both of these issues. Since JSPs are translated into Java servlets, they are only loaded and initialized once. Once the generated servlet is loaded into memory, it can handle many simultaneous requests . Since servlets run inside a protective sandbox that is provided by the Java Virtual Machine, security is not an issue. Using JSPs and Servlets gives developers access to all Java APIs as well as the object-oriented features of Java. JSPs also facilitate the separation of the GUI design from coding; the ability to edit using a GUI WYSIWYG editor is an additional benefit of JSPs.

All JSPs must run inside an application server that adheres to the Servlet and JSP specifications. There are many J2EE application servers available on many different platforms, meaning your application can be built independent of both. A JSP application built on one vendor s implementation of the specification will run on another vendor s version.

Note  

The feature that differentiates an application server from a web server is its capability to provide a Java environment that supports the services outlined in the J2EE specification (servlets, JSPs, etc.). Microsoft s IIS product is a special case: it is considered an application server because it provides a .NET environment as opposed to a Java environment. Oracle Application Server 10g does this via the use of a technology called Oracle Application Server Containers for J2EE (OC4J), which supports all of the services in the J2EE 1.4 technology stack.

Most vendors also provide many value-added features with their implementation of the application server. Sometimes, these features cause a tight coupling between your application and a particular vendor. Oracle, however, has embraced the open source community and has incorporated many open source tools into Oracle Application Server 10 g . As an example, the Oracle HTTP Server is based on the open source Apache HTTPD server. Oracle s Application Development Framework contains many value-added features that support the rapid development of applications that use JSPs as their presentation layer. JDeveloper, provides more information on Oracle ADF.

Developing any application usually involves a team of people that have varying levels of knowledge. Some team members may be very strong at presentations using HTML but are not well-versed in developing and designing Java classes. JSPs allow you to split development tasks among different team members according to their skill sets. Developers that are Java-focused can be tasked with the development of the servlets, tag libraries, and other required Java code. The JSP developers can then focus on the creation of the user interface and presentation logic using the JavaBeans and tag libraries.