JPanel

/** * * @author Aj Garcia */ import java.awt.Graphics; import javax.swing.JPanel; public class Painel extends JPanel{ public void paintComponent( Graphics g ){ super.paintComponent( g ); int pixel=0; for(pixel=0 ; pixel <= getHeight() ; pixel += 10){ g.drawLine(0, pixel, pixel, getHeight()); } for(pixel=getHeight() ; pixel >=0 ; pixel -= 10){ g.drawLine(0, pixel, getHeight() - pixel, 0); } for(pixel=0 ; pixel <= getHeight() ; pixel +=10){ g.drawLine(getWidth(), pixel, getWidth() - pixel, getHeight()); } for(pixel=getHeight() ; pixel >=0 ; pixel -= 10){ g.drawLine(getWidth(), pixel, getWidth() - (getHeight() - pixel), 0); } } }