by Dinesh Thakur

There are several kinds of buttons in computer applications, buttons that you click on with the mouse pointer or that you activate with a key stroke. Buttons provide a way to tell the computer what to do. The buttons with the little round dots are called radio buttons, and they always come in groups of two or more. A set of radio buttons is a visual clue that you only have a choice of one of those options. Choosing another button automatically turns off the button that was currently selected, just like pressing a button on your car radio switches you from one station to the next.

Like other buttons, radio buttons are mostly found in a graphical user interface like the Macintosh or Windows or Presentation Manager, but they're popping up in text-mode programs, too. Compare radio buttons with checkbox buttons, where you can choose as many of the checkboxes as you like.

import java.awt.*;

import javax.swing.*;
import java.awt.event.*;
public class JavaExampleMenuRadioButtonInJApplet extends JApplet implements ItemListener
     {
        ImageIcon Icn = new ImageIcon("item.jpg");
        JRadioButtonMenuItem
        RdoBtnMnuItem1 = new JRadioButtonMenuItem("Item 1", Icn),
        RdoBtnMnuItem2 = new JRadioButtonMenuItem("Item 2", Icn),
        RdoBtnMnuItem3 = new JRadioButtonMenuItem("Item 3", Icn),
        RdoBtnMnuItem4 = new JRadioButtonMenuItem("Item 4", Icn);
        public void init()
         {
             Container Cntnr = getContentPane();
             JMenuBar MnuBar = new JMenuBar();
             JMenu Mnu = new JMenu("Radio Button Menu Items");
             Mnu.add(RdoBtnMnuItem1);
             Mnu.add(RdoBtnMnuItem2);
             Mnu.add(RdoBtnMnuItem3);
             Mnu.add(RdoBtnMnuItem4);
             ButtonGroup BtnGrp = new ButtonGroup();
             BtnGrp.add(RdoBtnMnuItem1);
             BtnGrp.add(RdoBtnMnuItem2);
             BtnGrp.add(RdoBtnMnuItem3);
             BtnGrp.add(RdoBtnMnuItem4);
             RdoBtnMnuItem1.addItemListener(this);
             RdoBtnMnuItem2.addItemListener(this);
             RdoBtnMnuItem3.addItemListener(this);
             RdoBtnMnuItem4.addItemListener(this);
             MnuBar.add(Mnu);
             setJMenuBar(MnuBar);
         }
             public void itemStateChanged(ItemEvent e1)
              {
                 JMenuItem MnuItem= (JMenuItem) e1.getSource();
                 String ItmTxt = MnuItem.getText();
                 if(e1.getStateChange() == ItemEvent.SELECTED)
                 ItmTxt += " was selected";
                 else
                 ItmTxt += " was deselected";
             showStatus(ItmTxt);
              }
  }
/*<APPLET CODE = JavaExampleMenuRadioButtonInJApplet.class WIDTH = 350 HEIGHT = 280 ></APPLET>*/

Menu Radio Button Java Example