import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class OvalPanelCanvas extends JPanel {
public OvalPanelCanvas() {
}
public void paintComponent(Graphics g) {
int width = getWidth();
int height = getHeight();
g.setColor(Color.black);
g.drawOval(0, 0, width, height);
}
public static void main(String args[]) {
JFrame frame = new JFrame("Oval Sample");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new OvalPanelCanvas());
frame.setSize(300, 200);
frame.setVisible(true);
}
}