Java Web Technology

A Web application is a dynamic extension of a Web server. There are two types of Web applications. (1) A presentation-oriented Web application generates dynamic Web pages containing various types of markup language (HTML, XML, and so on) in response to requests. (2) A service-oriented Web application implements the endpoint of a fine-grained Web service. Service-oriented Web applications are often invoked by presentation-oriented applications.

In the Java 2 Platform, Web components provide the dynamic extension capabilities for a Web server. Web components are either Java Servlets or JSP pages. Servlets are Java programming language classes that dynamically process requests and construct responses. JSP pages are text-based documents that execute as servlets but allow a more natural approach to creating static content. Although servlets and JSP pages can be used interchangeably, each has its own strengths. Servlets are best suited to service-oriented Web applications and managing the control functions of a presentation-oriented application, such as dispatching requests and handling nontextual data. JSP pages are more appropriate for generating text-based markup such as HTML, SVG, WML, and XML.

Web components are supported by the services of a runtime platform called a Web container. The Web container provides services such as request dispatching, security, concurrency, and life cycle management. It also gives Web components access to APIs such as naming, transactions, and e-mail.

Most Web applications use the HTTP protocol, and support for HTTP is a major aspect of Web components.

HTTP
Servlets
Java Server Pages