JButton durch Grafik ersetzen

			JButton jOkButton = jOkButton(icon);
		        jOkButton.setPreferredSize(new Dimension(33,18));
			jOkButton.setVerticalAlignment(SwingConstants.CENTER);
		        jOkButton.setHorizontalAlignment(SwingConstants.LEFT);

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

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

public class ButtonExample extends JFrame implements ActionListener {

	private JButton btn1 = new JButton(new ImageIcon("b1.jpg"));

	private JButton btn2 = new JButton(new ImageIcon("b1.jpg"));

	private JButton btn3 = new JButton(new ImageIcon("b1.jpg"));

	private JButton btn4 = new JButton(new ImageIcon("b1.jpg"));

	private JButton btn5 = new JButton(new ImageIcon("b1.jpg"));

	public ButtonExample() {
		super("Button Example");
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		this.setAlwaysOnTop(true);
		this.setLocationByPlatform(true);
		this.setSize(480, 640);

		btn1.setName("b1");
		btn2.setName("b2");
		btn3.setName("b3");
		btn4.setName("b4");
		btn5.setName("b5");
		btn1.addActionListener(this);
		btn2.addActionListener(this);
		btn3.addActionListener(this);
		btn4.addActionListener(this);
		btn5.addActionListener(this);

		btn1.setMargin(new Insets(0, 0, 0, 0));
		btn1.setBorderPainted(false);
		btn1.setContentAreaFilled(false);
		btn1.setFocusPainted(false);

		btn2.setMargin(new Insets(0, 0, 0, 0));
		btn2.setBorderPainted(false);
		btn2.setContentAreaFilled(false);

		btn3.setMargin(new Insets(0, 0, 0, 0));
		btn3.setBorderPainted(false);

		btn4.setMargin(new Insets(0, 0, 0, 0));

		this.setLayout(new FlowLayout());
		this.add(btn1);
		this.add(btn2);
		this.add(btn3);
		this.add(btn4);
		this.add(btn5);

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

	public static void main(String[] args) {
		new ButtonExample();
	}

	public void actionPerformed(ActionEvent e) {
		JButton b = (JButton) e.getSource();
		if (b.getName().equals("b1"))
			System.out.println("b1");
		else if (b.getName().equals("b2"))
			System.out.println("b2");
		else if (b.getName().equals("b3"))
			System.out.println("b3");
		else if (b.getName().equals("b4"))
			System.out.println("b4");
		else
			System.out.println("b5");
	}
}