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

public class JCircle extends JPanel {
  private Ellipse2D.Double circle =
    new Ellipse2D.Double(10, 10, 30, 30);

  public void paintComponent(Graphics g) {
    clear(g);
    Graphics2D g2d = (Graphics2D)g;
    g2d.setStroke(new BasicStroke(3));
    g2d.draw(circle);
  }

  // super.paintComponent clears offscreen pixmap,
  // since we're using double buffering by default.

  protected void clear(Graphics g) {
    super.paintComponent(g);
  }

  protected Ellipse2D.Double getCircle() {
    return(circle);
  }

  public static void main(String[] args) {
    WindowUtilities.openInJFrame(new JCircle(), 380, 400);
  }
}