Radio buttons behave in the same mutually exclusive way in Swing and the AWT. However, the way that you create a set of radio buttons differs significantly between Swing and the AWT. To create a set of radio buttons in Swing, you must instantiate the buttons, instantiate a ButtonGroup object, and add the buttons to the ButtonGroup object. With the AWT, you must create a group object and pass it to the constructor for the buttons when they are instantiated. This code was tested using JDK1.1.6 and Swing 1.0.3 under Win95.
import java.awt.*;import java.awt.event.*;import java.util.*;import com.sun.java.swing.*;//=======================================================//public class SwingRadioButton01 extends JFrame{ public static void main(String[] args){ new SwingRadioButton01(); }//end main SwingRadioButton01(){//constructor //Create three radio buttons JRadioButton aButton = new JRadioButton("A",true); JRadioButton bButton = new JRadioButton("B"); JRadioButton cButton = new JRadioButton("C"); //Create a ButtonGroup object, add buttons to the group ButtonGroup myButtonGroup = new ButtonGroup(); myButtonGroup.add(aButton); myButtonGroup.add(bButton); myButtonGroup.add(cButton); //Display radio buttons getContentPane().setLayout(new FlowLayout()); getContentPane().add(aButton); getContentPane().add(bButton); getContentPane().add(cButton); setSize(250,100); setTitle("Swing Radio Buttons"); setVisible(true); // Inner class to terminate program. addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0);}});//end WindowListener }//end constructor}//end class SwingRadioButton01 definition