I need to make a graph in Java that will output data about book sales on Amazon. Help, please!?

I have found the following base program from Ian Darwin:

package org.me.mylib;

/**

*

* @author Ian Darwin

*/

import java.awt.Dimension;

import java.awt.Graphics;

import java.awt.geom.Point2D;

import java.io.IOException;

import java.io.InputStreamReader;

import java.util.ArrayList;

import java.util.List;

import javax.swing.JFrame;

import javax.swing.JPanel;

//import com.darwinsys.util.Debug;

/** Simple Graphing program.

* @author Ian F. Darwin, http://www.darwinsys.com/

* @version $Id: Grapher.java,v 1.20 2008/10/06 15:44:34 ian Exp $

*/

public class Grapher extends JPanel {

private static final long serialVersionUID = -1813143391310613248L;

/** Multiplier for range to allow room for a border */

public final static double BORDERFACTOR = 1.1f;

/** The list of Point points. */

protected List<Point2D> data;

/** The minimum and maximum X values */

protected double minx = Integer.MAX_VALUE, maxx = Integer.MIN_VALUE;

/** The minimum and maximum Y values */

protected double miny = Integer.MAX_VALUE, maxy = Integer.MIN_VALUE;

/** The range of X and Y values */

protected double xrange, yrange;

public Grapher() {

data = new ArrayList<Point2D>();

figure();

}

/** Set the list data from a list of Strings, where the

* x coordinate is incremented automatically, and the y coordinate

* is made from the String in the list.

*/

public void setListDataFromYStrings(List<String> newData) {

data.clear();

for (int i=0; i < newData.size(); i++) {

Point2D p = new Point2D.Double();

p.setLocation(i, java.lang.Double.parseDouble(newData.get(i)));

data.add(p);

}

figure();

}

/** Set the list from an existing List, as from GraphReader.read() */

public void setListData(List<Point2D> newData) {

data = newData;

figure();

}

/** Compute new data when list changes */

private void figure() {

// find min & max

for (int i=0 ; i < data.size(); i++) {

Point2D d = (Point2D)data.get(i);

if (d.getX() < minx) minx = d.getX();

if (d.getX() > maxx) maxx = d.getX();

if (d.getY() < miny) miny = d.getY();

if (d.getY() > maxy) maxy = d.getY();

}

// Compute ranges

xrange = (maxx - minx) * BORDERFACTOR;

yrange = (maxy - miny) * BORDERFACTOR;

//Debug.println("range", "minx,x,r = " + minx +' '+ maxx +' '+ xrange);

//Debug.println("range", "miny,y,r = " + miny +' '+ maxy +' '+ yrange);

}

/** Called when the window needs painting.

* Computes X and Y range, scales.

*/

@Override

public void paintComponent(Graphics g) {

super.paintComponent(g);

Dimension s = getSize();

if (data.size() < 2) {

g.drawString("Insufficient data: " + data.size(), 10, 40);

return;

}

// Compute scale factors

double xfact = s.width / xrange;

double yfact = s.height / yrange;

// Scale and plot the data

for (int i=0 ; i < data.size(); i++) {

Point2D d = (Point2D)data.get(i);

double x = (d.getX() - minx) * xfact;

double y = (d.getY() - miny) * yfact;

Debug.println("point", "AT " + i + " " + d + "; " +

"x = " + x + "; y = " + y);

// Draw a 5-pixel rectangle centered, so -2 both x and y.

// AWT numbers Y from 0 down, so invert:

g.drawRect(((int)x)-2, s.height-2-(int)y, 5, 5);

}

}

@Override

public Dimension getPreferredSize() {

return new Dimension(150, 150);

}

public static void main(String[] args) throws IOException {

final JFrame f = new JFrame("Grapher");

f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

Grapher grapher = new Grapher();

f.setContentPane(grapher);

f.setLocation(100, 100);

f.pack();

List<Point2D> data = null;

if (args.length == 0)

data = org.me.mylib.Grapher.class.getName();

else {

String fileName = args[0];

if ("-".equals(fileName)) {

data = GraphReader.read(new InputStreamReader(System.in), "System.in");

} else {

org.me.mylib.Grapher.class.getField(fileName);

}

}

grapher.setListData(data);

f.setVisible(true);

}

}

I need to add more detail to get it to show lines and there are some mistakes because of my changes in the program. Can anybody help me?