JScrollPane override setHvalue

I would like to modify my JScrollPane so that when the horizontal position is changed, the position hvalue is sent to another class. I don't want the other class to have to retrieve this value every time as this will happen repeatedly during a task which must be finished as quickly as possible.
I haven't been able to find any documentation on the exact syntax used by default but I'm guessing what I want will look something like this:

import java.lang.Math.*;
import javax.swing.*;

public class scroll {
public static void main(String[] args) {
	JFrame f = new JFrame();
	f.setDefaultCloseOperation(3);
	panel p = new panel();
	
	JScrollPane sp = new JScrollPane(p,21,31) {
		@Override
		public final void setHvalue(double value) {
			hvalue = value;
			p.sendH((int) Math.round(value));
		}
	};
	
	f.add(sp);
	f.setSize(333,333);
	f.setVisible(true);
}
}

which will include a panel object governed by the class:

import javax.swing.*;

public class panel extends JPanel {

private static int H;
public panel() {}

public static void sendH(int x) {
	H=x;
	System.out.println(x);
}
}

Attempting to compile this code yields the error messages:

• scroll.java.11: error: method does not override or implement a method from supertype

• @Override

• scroll.java.13: error: cannot find symbol

• hvalue = value;

• symbol: variable hvalue

which, as I understand it, is basically their way of saying I can't modify setHvalue(). Is there some way around this or an alternative way of sending hvalue when it's changed instead of retrieving it every time it's needed?

> when the horizontal position is changed, the position hvalue is sent to another class.

This is done by adding an AdjustmentListener to the horizontal scrollbar.

However, this is extra overhead that is NOT required if you do not use the information every time it changes.

I do not recommend using this approach.

> I don't want the other class to have to retrieve this value every time as this will happen repeatedly during a task which must be finished as quickly as possible.

Invoking the getValue() method of the scrollbar will NOT add any measurable overhead to your task.

Your task just needs a reference to the scroll pane so you can access the scrollbar and get the current value.

Actually I figured out the answer, sorry about that. It turns out that the method getHvalue is only for awt ScrollPane and is not inherited by swing JScrollPane. I will post a working version here, in case someone else is interested some day (although I'm guessing that camickr's approach is better).
The JScrollPane class is:

import java.awt.*;
import javax.swing.*;
import javax.accessibility.*;

public class scroll {
public static void main(String[] args) {
	JFrame f = new JFrame();
	f.setDefaultCloseOperation(3);
	panel p = new panel() {
		@Override
		public Dimension getMinimumSize(){
			return new Dimension(getWidth(),getHeight());
		}
		@Override
		public Dimension getPreferredSize(){
			return new Dimension(getWidth(),getHeight());
		}
		@Override
		public Dimension getMaximumSize(){
			return new Dimension(getWidth(),getHeight());
		}
	};
	
	JScrollPane sp = new JScrollPane(p,22,32);
	sp.setHorizontalScrollBar( new JScrollBar(JScrollBar.HORIZONTAL){
		@Override
		public void setValue(int value) {
			BoundedRangeModel m = getModel();
			int oldValue = m.getValue();
			m.setValue(value);

			if (accessibleContext != null) {
				accessibleContext.firePropertyChange(
				AccessibleContext.ACCESSIBLE_VALUE_PROPERTY,
				Integer.valueOf(oldValue),
				Integer.valueOf(m.getValue()));
			}
			
			p.sendH(value);
		}
	});
	
	f.add(sp);
	f.setSize(333,333);
	p.setSize(400,400);
	f.setVisible(true);
}
}

and the panel class is:

import javax.swing.*;

public class panel extends JPanel {

private static int H;
public panel() {}

public static void sendH(int x) {
	H=x;
	System.out.println(x);
}
}