Java ImageIcon create

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;

public class Main extends JFrame {
  public Main() {
    super("JButton");

    setDefaultCloseOperation(EXIT_ON_CLOSE);
    setLayout(new FlowLayout());

    Icon icon = new ImageIcon(getClass().getResource("icon.png"));
    //from   w ww. j  a  v a 2  s  .c om
    JButton closeButton1 = new JButton("Close", icon);
    getContentPane().add(closeButton1);
  }

  public static void main(String[] args) {
    Main frame = new Main();
    frame.pack();
    frame.setVisible(true);
  }
}