Basic-Servlets-Examples

The servlet can be created by three ways:

• By implementing Servlet interface,
• By inheriting GenericServlet class, (or)
• By inheriting HttpServlet class

GenericServlet

• Implements  Servlet, ServletConfig andSerializable interface.
• It provides the implementaion of all the methods of these interfaces except the service method.
• GenericServlet class can handle any type of request so it is protocol-independent.

HttpServlet

• class extends the GenericServlet class and implements Serializable interface.
• It provides http specific methods such as doGet, doPost, doHead, doTrace etc

Package and Deployment

Deployment Descriptor :

• web.xml is the deployment descriptor for web applications.
• Every web application module must have a single web.xml file in the folder root/WEB-INF

<web-app>
  <servlet>
    <servlet-name>GenericServlet</servlet-name>
    <servlet-class>com.suneet.GenericServletExample</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>GenericServlet</servlet-name>
    <url-pattern>/exampleservlet</url-pattern>
  </servlet-mapping>
</web-app>