JProgressBar Imagem

package exps;

import java.awt.Color;
import java.awt.Graphics;
import javax.swing.ImageIcon;
import javax.swing.JComponent;
import javax.swing.JProgressBar;
import javax.swing.plaf.basic.BasicProgressBarUI;

public class NovaProgressBar extends BasicProgressBarUI {
    
    private ImageIcon img = new ImageIcon(getClass().getResource("demobar.png"));

    @Override
    protected void paintDeterminate(Graphics g, JComponent c){
        int size = 0;
        double percentComplete;
        int imageWidth=0;
        int imageHeight=0;
        try{
            JProgressBar pb = (JProgressBar) c;
            percentComplete = pb.getPercentComplete();
            size = pb.getWidth();
            imageHeight = pb.getHeight();
            imageWidth = new Double(percentComplete*size).intValue();
            g.drawImage(img.getImage(), 0, 0, imageWidth, imageHeight, Color.WHITE, null);
        } catch(ClassCastException e) {
            e.printStackTrace();        
        }
    }
}