Java - Repeat Image

package cespin;

import javax.swing.*;

public class FrameConFondo extends JFrame {

	FrameConFondo(){

		add(new PanelImagen());

		setSize(270,270);

		setVisible(true);

		setLocationRelativeTo(null);

	}

	public static void main (String args[]){

		FrameConFondo f = new FrameConFondo();

	}

}

package cespin;

import java.awt.*;

import javax.swing.*;

public class PanelImagen extends JPanel {

	public void paintComponent(Graphics g){

		Dimension tam = getSize();

		ImageIcon imagen = new ImageIcon(new ImageIcon(getClass().getResource("/imagen/cespin.png")).getImage());

		g.drawImage(imagen.getImage(),0,0,tam.width,tam.height,null);

	}

}