Java tutorial
import java.awt.Container; import java.awt.GridLayout; import javax.swing.JButton; import javax.swing.JFrame; public class GridTest extends JFrame { public static void main(String[] args) { int rows = 2; int cols = 3; GridTest gt = new GridTest(rows, cols); gt.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); gt.pack(); gt.setVisible(true); } public GridTest(int rows, int cols) { Container pane = getContentPane(); pane.setLayout(new GridLayout(rows, cols)); for (int i = 0; i < 20; i++) { JButton button = new JButton(Integer.toString(i + 1)); pane.add(button); } } }