Using Abstract Classes

<%! javax.servlet.jsp.JspWriter pw; abstract class Rectangle { int length, breadth, area; abstract int getArea() throws java.io.IOException; public void setArea(int length, int breadth) throws java.io.IOException { this.length = length; this.breadth = breadth; pw.println("Calculating the area of a rectangle...........
"); pw.println("The area of rectangle is "); pw.println(getArea()); } } class Rectangle1 extends Rectangle { int getArea() throws java.io.IOException { area = length*breadth; return(area); } } %> <% pw = out; Rectangle1 rect = new Rectangle1(); rect.setArea(2,3); %>