import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
public class IconButton {
public static void main(String args[]) {
JFrame frame = new JFrame("DefaultButton");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Icon warnIcon = new ImageIcon("yourFile.gif");
JButton button2 = new JButton(warnIcon);
frame.add(button2);
frame.setSize(300, 200);
frame.setVisible(true);
}
}