import java.awt.Color;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.geom.Rectangle2D;
import javax.swing.JComponent;
import javax.swing.JFrame;
public class MainClass{
public static void main(String[] args) {
JFrame jf = new JFrame("Demo");
Container cp = jf.getContentPane();
MyCanvas tl = new MyCanvas();
cp.add(tl);
jf.setSize(300, 200);
jf.setVisible(true);
}
}
class MyCanvas extends JComponent {
Shape shape;
public MyCanvas() {
shape = create();
}
protected Shape create() {
float cm = 72 / 2.54f;
return new Rectangle2D.Float(cm, cm, 2 * cm, cm);
}
public void paint(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setPaint(Color.black);
g2.draw(shape);
}
}