package usestroke;import java.awt.*;import javax.swing.JPanel;import java.awt.geom.*;/** * Title: * Description: * Copyright:    Copyright (c) 2001 * Company: * @author * @version 1.0 */public class MyPanel extends JPanel {  BorderLayout borderLayout1 = new BorderLayout();  private Ellipse2D.Double circle =    new Ellipse2D.Double(10, 10, 350, 350);  private GradientPaint gradient =    new GradientPaint(0, 0, Color.red, 175, 175, Color.yellow,true);  public MyPanel() {    try {      jbInit();    }    catch(Exception ex) {      ex.printStackTrace();    }  }  void jbInit() throws Exception {    this.setLayout(borderLayout1);  }  public void paintComponent(Graphics g) {    clear(g);    Graphics2D g2d = (Graphics2D)g;    g2d.setPaint(gradient);    g2d.fill(circle);    g2d.setColor(Color.blue);    g2d.setStroke(new BasicStroke(1));    g2d.draw(circle);    for(int i=9;i>0;i--){      g2d.setStroke(new BasicStroke(i));      g2d.draw(new Ellipse2D.Double(10+i*20, 10+i*20, 350-i*30, 350-i*30));    }  }  protected void clear(Graphics g) {    super.paintComponent(g);  }}