Change JButton with BasicButtonUI in Java

import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
/*from  ww w . j a v  a2 s. c om*/
import javax.swing.AbstractButton;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.border.Border;
import javax.swing.plaf.ComponentUI;
import javax.swing.plaf.basic.BasicButtonUI;

public class Main {

  public static void main(String argv[]) {
    JFrame f = new JFrame();
    f.setSize(400, 300);
    f.getContentPane().setLayout(new FlowLayout());

    JPanel p = new JPanel();
    JButton bt1 = new JButton("Click Me");
    bt1.setUI(new MyButtonUI());
    p.add(bt1);
    f.getContentPane().add(p);
    WindowListener wndCloser = new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    };
    f.addWindowListener(wndCloser);
    f.setVisible(true);
  }
}

class MyButtonUI extends BasicButtonUI implements java.io.Serializable,
    MouseListener, KeyListener {

  private final static MyButtonUI m_buttonUI = new MyButtonUI();

  protected Border m_borderRaised = UIManager.getBorder("Button.border");

  protected Border m_borderLowered = UIManager
      .getBorder("Button.borderPressed");

  protected Color m_backgroundNormal = UIManager
      .getColor("Button.background");

  protected Color m_backgroundPressed = UIManager
      .getColor("Button.pressedBackground");

  protected Color m_foregroundNormal = UIManager
      .getColor("Button.foreground");

  protected Color m_foregroundActive = UIManager
      .getColor("Button.activeForeground");

  protected Color m_focusBorder = UIManager.getColor("Button.focusBorder");

  public static ComponentUI createUI(JComponent c) {
    return m_buttonUI;
  }

  public void installUI(JComponent c) {
    super.installUI(c);

    c.addMouseListener(this);
    c.addKeyListener(this);
  }

  public void uninstallUI(JComponent c) {
    super.uninstallUI(c);
    c.removeMouseListener(this);
    c.removeKeyListener(this);
  }

  public void paint(Graphics g, JComponent c) {
    AbstractButton b = (AbstractButton) c;
    Dimension d = b.getSize();

    g.setFont(c.getFont());
    FontMetrics fm = g.getFontMetrics();

    g.setColor(b.getForeground());
    String caption = b.getText();
    int x = (d.width - fm.stringWidth(caption)) / 2;
    int y = (d.height + fm.getAscent()) / 2;
    g.drawString(caption, x, y);

  }

  public Dimension getPreferredSize(JComponent c) {
    Dimension d = super.getPreferredSize(c);
    if (m_borderRaised != null) {
      Insets ins = m_borderRaised.getBorderInsets(c);
      d.setSize(d.width + ins.left + ins.right, d.height + ins.top
          + ins.bottom);
    }
    return d;
  }

  public void mouseClicked(MouseEvent e) {
  }

  public void mousePressed(MouseEvent e) {
    JComponent c = (JComponent) e.getComponent();
    c.setBorder(m_borderLowered);
    c.setBackground(m_backgroundPressed);
  }

  public void mouseReleased(MouseEvent e) {
    JComponent c = (JComponent) e.getComponent();
    c.setBorder(m_borderRaised);
    c.setBackground(m_backgroundNormal);
  }

  public void mouseEntered(MouseEvent e) {
    JComponent c = (JComponent) e.getComponent();
    c.setForeground(m_foregroundActive);
    c.repaint();
  }

  public void mouseExited(MouseEvent e) {
    JComponent c = (JComponent) e.getComponent();
    c.setForeground(m_foregroundNormal);
    c.repaint();
  }

  public void keyTyped(KeyEvent e) {
  }

  public void keyPressed(KeyEvent e) {
    int code = e.getKeyCode();
    if (code == KeyEvent.VK_ENTER || code == KeyEvent.VK_SPACE) {
      JComponent c = (JComponent) e.getComponent();
      c.setBorder(m_borderLowered);
      c.setBackground(m_backgroundPressed);
    }
  }

  public void keyReleased(KeyEvent e) {
    int code = e.getKeyCode();
    if (code == KeyEvent.VK_ENTER || code == KeyEvent.VK_SPACE) {
      JComponent c = (JComponent) e.getComponent();
      c.setBorder(m_borderRaised);
      c.setBackground(m_backgroundNormal);
    }
  }

}