Set gap for components inside GridLayout in Java

/*from   ww  w.j  a v a 2 s.co m*/
import java.awt.GridLayout;

import javax.swing.JButton;
import javax.swing.JFrame;

public class Main {

  public static void main(String[] args) {
    JFrame frame = new JFrame("GridLayout Test");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setLayout(new GridLayout(3, 2, 30, 20));
    frame.add(new JButton("Button 1"));
    frame.add(new JButton("Button 2"));
    frame.add(new JButton("Button 3"));
    frame.add(new JButton("Button 4"));
    frame.add(new JButton("Button 5"));
    frame.add(new JButton("Button 6"));
    frame.add(new JButton("Button 7"));
    frame.add(new JButton("Button 8"));
    frame.pack();
    frame.setVisible(true);
  }
}