Contenedores iniciales
public class FrameTester {
public static void main (String args[]) {
JFrame f = new JFrame ("JFrame Example");
Container c = f.getContentPane(); c.setLayout (new FlowLayout());
for (int i = 0; i < 5; i++) {
c.add (new JButton ("No")). setBackground(SystemColor.control);
c.add (new Button ("Batter"));
c.add (new JLabel ("Swing"));