XML by Example

Figure A.6: The servlet in a Web browser

The descendant has all the methods and fields defined in its ancestor, plus

any new fields or method it decides to implement.

Inheritance is indicated with the

extends keyword followed by the ancestor

name. In Java, a class cannot inherit from more than one class (single

inheritance). In the following example, XDic inherits from HttpServlet:

public class XDic

extends HttpServlet

{

// ...

}

doGet()

Java servlets must inherit from HttpServlet and overwrite one or more

methods among

doGet(), doPost(), and doPut(). Each of these methods cor-

responds to an HTTP command. In Listing A.2, the servlet overwrites

doGet()