Creating Image Radio Buttons
When using an image to represent the state of a radio button, it is necessary to provide it with two images - one that represents the ``selected'' state and another to represent the ``unselected'' state. The ``unselected'' image is assigned via the JRadioButton constructor while the ``selected'' image is assigned via the method setSelectedIcon(). 

 
 ButtonGroup group = new ButtonGroup();
     
 JRadioButton b1 = new JRadioButton("image1.gif");
 b1.setSelectedIcon(new ImageIcon("images1s.gif"));
 b1.addActionListener(actionListener);
 group.add(b1);
     
 JRadioButton b2 = new JRadioButton("image1.gif");
 b1.setSelectedIcon(new ImageIcon("images2s.gif"));
 b2.addActionListener(actionListener);
 group.add(b2);
     
 // Set one of the radio buttons on.
 group.setSelected(b1.getModel(), true);