Java AWT GridBagConstraints class

import java.awt.GridBagLayout;
import java.awt.Container;
import javax.swing.JFrame;
import javax.swing.JButton;
import java.awt.GridBagConstraints;

public class Main {
    public static void main(String[] args) {
        String title = "GridBagLayout with gridx and gridy";
        JFrame frame = new JFrame(title);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        Container contentPane = frame.getContentPane();
        contentPane.setLayout(new GridBagLayout());

        // Create an object for GridBagConstraints to set 
        // the constraints for each JButton 
        GridBagConstraints gbc = new GridBagConstraints();

        for (int y = 0; y < 3; y++) {
            for (int x = 0; x < 3; x++) {
                gbc.gridx = x;/*from ww  w . j a v a2  s .c  o m*/
                gbc.gridy = y;
                String text = "Button (" + x + ", " + y + ")";
                contentPane.add(new JButton(text), gbc);
            }
        }

        frame.pack();
        frame.setVisible(true);
    }
}