Servlet Basics - Developing Java Servlets - page 23

L ISTING 3.1

Continued

//Get Servlet information
public String getServletInfo() {

return “BasicServlet Information”;

}

}

Dissecting the BasicServlet
Now that you have had a chance to look over the source of the BasicServlet , let's take a
closer look at each of its integral parts. We will examine where the servlet fits into the JSDK
framework, the methods that the servlet implements, and the objects being used by the servlet.

Where Does the BasicServlet Fit into the Servlet
Framework?
The first thing we are going to look at is where the BasicServlet fits into the servlet frame-
work. This servlet extends the HttpServlet class. The HttpServlet class is an abstract class
that simplifies writing HTTP servlets. It extends the GenericServlet class and provides the
functionality for handling the HTTP protocol-specific requests. The BasicServlet overrides
four of its inherited methods. Figure 3.1 shows where the BasicServlet fits into this hierarchy.

3

<<Interface>>
javax.servlet.ServletConfig

<<Interface>>
javax.servlet.Servlet

<<Interface>>
java.io.Serializable

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

BasicServlet

F IGURE 3.1
The BasicServlet depicted in the Servlet Framework.