import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;
import java.awt.geom.RoundRectangle2D;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.UIManager;

public class DrawFrame extends JFrame
{
  public DrawFrame()
  {
    setLayout(new BorderLayout());
    getContentPane().add(new DrawComponent(), BorderLayout.CENTER);
  }

  public static class DrawComponent extends JComponent
  {
    public void paintComponent(Graphics g)
    {
      Graphics2D g2d = (Graphics2D)g;
      g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
        RenderingHints.VALUE_ANTIALIAS_ON);
      g2d.setStroke(new BasicStroke(3.0f));

      // -----------------------------------------------------------------
      // Put your implementation here
      // -----------------------------------------------------------------

    }
  }

  public void center()
  {
    Dimension screenSize = getToolkit().getScreenSize();
    Dimension frameSize = getSize();
    Point location = new Point((screenSize.width - frameSize.width) / 2,
      (screenSize.height - frameSize.height) / 2);
    setLocation(location);
  }

  public static void main(String[] args) throws Exception
  {
    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    JFrame.setDefaultLookAndFeelDecorated(true);
    
    DrawFrame f = new DrawFrame();
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setSize(new Dimension(400, 400));
    f.center();
    f.setVisible(true);
  }
}