public static ComponentUI createUI(JComponent b) 
{
    // ********************************
    //        Create PLAF
    // ********************************
        return radioButtonUI;
}

 public Icon getDefaultIcon() 
{
        return icon;
}

 public Dimension getPreferredSize(JComponent c) 
{
                
        if(c.getComponentCount()  > 0) {
            return null;
        }
        AbstractButton b = (AbstractButton) c;
        String text = b.getText();
        Icon buttonIcon = (Icon) b.getIcon();
        if(buttonIcon == null) {
            buttonIcon = getDefaultIcon();
        }
        Font font = b.getFont();
        FontMetrics fm = b.getFontMetrics(font);
        prefViewRect.x = prefViewRect.y = 0;
        prefViewRect.width = Short.MAX_VALUE;
        prefViewRect.height = Short.MAX_VALUE;
        prefIconRect.x = prefIconRect.y = prefIconRect.width = prefIconRect.height = 0;
        prefTextRect.x = prefTextRect.y = prefTextRect.width = prefTextRect.height = 0;
        SwingUtilities.layoutCompoundLabel(
            c, fm, text, buttonIcon,
            b.getVerticalAlignment(), b.getHorizontalAlignment(),
            b.getVerticalTextPosition(), b.getHorizontalTextPosition(),
            prefViewRect, prefIconRect, prefTextRect,
            text == null ? 0 : b.getIconTextGap());
        // find the union of the icon and text rects (from Rectangle.java)
        int x1 = Math.min(prefIconRect.x, prefTextRect.x);
        int x2 = Math.max(prefIconRect.x + prefIconRect.width,
                          prefTextRect.x + prefTextRect.width);
        int y1 = Math.min(prefIconRect.y, prefTextRect.y);
        int y2 = Math.max(prefIconRect.y + prefIconRect.height,
                          prefTextRect.y + prefTextRect.height);
        int width = x2 - x1;
        int height = y2 - y1;
        prefInsets = b.getInsets(prefInsets);
        width += prefInsets.left + prefInsets.right;
        height += prefInsets.top + prefInsets.bottom;
        return new Dimension(width, height);
}

The preferred size of the radio button

 protected String getPropertyPrefix() 
{
        return propertyPrefix;
}

 protected  void installDefaults(AbstractButton b) 
{
        super.installDefaults(b);
        if(!defaults_initialized) {
            icon = UIManager.getIcon(getPropertyPrefix() + "icon");
            defaults_initialized = true;
        }
}

 public synchronized  void paint(Graphics g,
    JComponent c) 
{
             
        AbstractButton b = (AbstractButton) c;
        ButtonModel model = b.getModel();
        Font f = c.getFont();
        g.setFont(f);
        FontMetrics fm = SwingUtilities2.getFontMetrics(c, g, f);
        Insets i = c.getInsets();
        size = b.getSize(size);
        viewRect.x = i.left;
        viewRect.y = i.top;
        viewRect.width = size.width - (i.right + viewRect.x);
        viewRect.height = size.height - (i.bottom + viewRect.y);
        iconRect.x = iconRect.y = iconRect.width = iconRect.height = 0;
        textRect.x = textRect.y = textRect.width = textRect.height = 0;
        Icon altIcon = b.getIcon();
        Icon selectedIcon = null;
        Icon disabledIcon = null;
        String text = SwingUtilities.layoutCompoundLabel(
            c, fm, b.getText(), altIcon != null ? altIcon : getDefaultIcon(),
            b.getVerticalAlignment(), b.getHorizontalAlignment(),
            b.getVerticalTextPosition(), b.getHorizontalTextPosition(),
            viewRect, iconRect, textRect,
            b.getText() == null ? 0 : b.getIconTextGap());
        // fill background
        if(c.isOpaque()) {
            g.setColor(b.getBackground());
            g.fillRect(0,0, size.width, size.height);
        }
        // Paint the radio button
        if(altIcon != null) {
            if(!model.isEnabled()) {
                if(model.isSelected()) {
                   altIcon = b.getDisabledSelectedIcon();
                } else {
                   altIcon = b.getDisabledIcon();
                }
            } else if(model.isPressed() && model.isArmed()) {
                altIcon = b.getPressedIcon();
                if(altIcon == null) {
                    // Use selected icon
                    altIcon = b.getSelectedIcon();
                }
            } else if(model.isSelected()) {
                if(b.isRolloverEnabled() && model.isRollover()) {
                        altIcon = (Icon) b.getRolloverSelectedIcon();
                        if (altIcon == null) {
                                altIcon = (Icon) b.getSelectedIcon();
                        }
                } else {
                        altIcon = (Icon) b.getSelectedIcon();
                }
            } else if(b.isRolloverEnabled() && model.isRollover()) {
                altIcon = (Icon) b.getRolloverIcon();
            }
            if(altIcon == null) {
                altIcon = b.getIcon();
            }
            altIcon.paintIcon(c, g, iconRect.x, iconRect.y);
        } else {
            getDefaultIcon().paintIcon(c, g, iconRect.x, iconRect.y);
        }
        // Draw the Text
        if(text != null) {
            View v = (View) c.getClientProperty(BasicHTML.propertyKey);
            if (v != null) {
                v.paint(g, textRect);
            } else {
                paintText(g, b, textRect, text);
            }
            if(b.hasFocus() && b.isFocusPainted() &&
               textRect.width  > 0 && textRect.height  > 0 ) {
                paintFocus(g, textRect, size);
            }
        }
}

paint the radio button

 protected  void paintFocus(Graphics g,
    Rectangle textRect,
    Dimension size) 
{

}

 protected  void uninstallDefaults(AbstractButton b) 
{
        super.uninstallDefaults(b);
        defaults_initialized = false;
}