How to use Superclass Variables With Subclassed Objects in java

Using Superclass Variables With Subclassed Objects

<%!
javax.servlet.jsp.JspWriter localOut;

class vehicle
{
public void start() throws java.io.IOException
{
localOut.println("Starting...
");
}
}

class aircraft extends vehicle
{
public void fly() throws java.io.IOException
{
localOut.println("Flying...
");
}
}

class plane extends aircraft
{
public void fly() throws java.io.IOException
{
localOut.println("Flying...
");
}
}
%>
<%
localOut = out;

out.println();
out.println("Creating a plane object...
");
vehicle p = new plane();
p.start();
%>