To create a Web-based user interface, you need to apply Web-centric components. J2EE provides three types of Web-centric components:
JavaServer Pages (JSP)
The first two of these components (JSPs and servlets) provide services to clients that use HTTP as a means of communication. For example, JSPs and servlets can interact with the following clients:
Standard HTML browsers, such as Microsoft Internet Explorer and Netscape Navigator
Java 2 Micro Edition (J2ME) enabled devices, connecting across a wireless network
Any Java application using java.net.URL objects
Wireless Markup Language (WML) browsers, such as those found on WAP-enabled mobile phones
Web Services expose application or business logic to a client ...