import javax.swing.JFrame;
import javax.swing.JComponent;
import java.awt.Graphics;
import java.awt.Color;

class Program01 extends JFrame {
	SajatKomponens sk = new SajatKomponens();
	Program01() {
		this.add(sk);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		this.setSize(400, 300);
		this.setVisible(true);
	}
	public static void main(String args[]) {
		new Program01();
	}
}
class SajatKomponens extends JComponent {
	@Override
	public void paintComponent(Graphics g) {
		super.paintComponent(g);
		g.setColor(Color.BLUE);
		g.fillRect(30, 30, 100, 30);
	}	
}