Java Servlet API

The Java Servlet API is an extension to the standard Java packages and marks the first move of Java from the standard application domain to the server-side. This API aids developers in building powerful and efficient Web applications using a simple API. The entire HTTP protocol is encapsulated in a set of classes in the Java Servlet API.

The Java Servlet API enables development of Web application components that can be deployed on any Java Servlet API compliant servlet container. The API defines a set of classes for building generic servlets as well as HTTP protocol servlets. Apart from the support for the HTTP protocol, the Java Servlet API also provides useful features, such as filters and listeners, which enable application component providers to enhance their Web-application components.

When you use the Java Servlet API to build Web-application components, the servlet container guarantees that the Web application will receive the browser request data in the format it expects and can send back the response data in the format that the client browser expects. The Web-application-component provider can focus on writing the application logic for the component and need not worry about writing code to parse and interpret the format in which the client browser sends and receives data.