JRadioButton Example in Java for Beginners

This exhaustive example illustrates JRadioButton in Java for beginners. This tutorial covers all the core methods of javax.swing.JRadioButton class.

import javax.swing.*;
import java.awt.*;
import javax.swing.text.*;
class JRadioButtonExample extends JFrame
{
JPanel p;
JLabel label;
JRadioButton r1,r2,r3,r4,r5,r6,r7,r8;
ImageIcon i1,i2,i3,i4,i5,i6,i7;
ButtonGroup bg=new ButtonGroup();

    public JRadioButtonExample()
    {
        // Create and show the GUI
        createAndShowGUI();
    }
   
    private void createAndShowGUI()
    {
        // Set frame properties
        setTitle("JRadioButton Demo");
        setVisible(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       
        // Create image icons
        i1=new ImageIcon("radiobutton.png");
        i2=new ImageIcon("radiobuttonselected.png");
        i3=new ImageIcon("radiobuttonrollover.png");
        i4=new ImageIcon("radiobuttondisabled.png");
        i5=new ImageIcon("radiobuttonrolloverselected.png");
        i6=new ImageIcon("radiobuttonpressed.png");
        i7=new ImageIcon("radiobuttondisableselected.png");
       
        // Create JPanel
        // This panel holds all
        // the JRadioButtons
        p=new JPanel();
       
        // Set the GridBagLayout
        // for the panel
        p.setLayout(new GridBagLayout());

        // Create a JLabel
        // This acts as a status label
        // Initialize with text so that
        // it gets displayed before packing
        // other wise, the size would increase
        // when the text is updated, and packing
        // will be disturbed.
        label=new JLabel(" ");
       
        // First constructor
        // Creates a JRadioButton
        // with no text and icon
        // and deselected
        r1=new JRadioButton();
       
        // Create an AbstractAction
        // It is a class implementing the
        // Action interface
       
        // Make a beep sound
        Action a=new DefaultEditorKit.BeepAction();
       
        // Second constructor
        // This takes javax.swing.Action
        // object. This is fired whenever
        // some action is performed on r2 (here)
        r2=new JRadioButton(a);
       
        // Third constructor
        // This takes an ImageIcon
        // This icon appears instead of the original
        // UI representation of JRadioButton
        r3=new JRadioButton(i1);
       
        // Fourth constructor
        // This takes an ImageIcon and
        // a boolean value indicating
        // selection/deselection
        // The icon here is the default icon
        // (normal icon) not the selected icon
        // However, if there is no selected icon
        // set separately, the same icon appears
        r4=new JRadioButton(i1,true);
           
        // Fifth constructor
        // This takes String text which
        // acts as label for the JRadioButton
        r5=new JRadioButton("RadioButton 5");
       
        // Sixth constructor
        // This takes String text which acts
        // as label and boolean indicating selection/
        // deselection
        // selection=true,deselection=false
        r6=new JRadioButton("RadioButton 6",true);
   
        // Seventh constructor
        // This takes String label with an icon
        // that acts as the default icon
        r7=new JRadioButton("RadioButton 7",i1);
       
        // Eighth constructor
        // This takes String label, ImageIcon and
        // selection flag
        r8=new JRadioButton("RadioButton 8",i1,true);
       
        // Set some text
        r1.setText("Radio Button 1");
        r3.setText("Radio Button 3");
        r4.setText("Radio Button 4");
       
        // Set some icon for r1
        r1.setIcon(i1);
       
        // Set selected icon
        r1.setSelectedIcon(i2);
        r4.setSelectedIcon(i2);
        r7.setSelectedIcon(i2);
        r8.setSelectedIcon(i2);
       
        // Set roll over icon
        r1.setRolloverIcon(i3);
       
        // Set roll over selected icon
        r1.setRolloverSelectedIcon(i5);
       
        // Set pressed icon
        r1.setPressedIcon(i6);
   
        // Set disabled icon
        // Will only be dispalyed
        // if r3 is disabled
        r3.setDisabledIcon(i4);
       
        // Disable r3
        r3.setEnabled(false);
       
        // Make it selected
        r3.setSelected(true);
       
       
        // Set disabled selected icon
        r3.setDisabledSelectedIcon(i7);
       
        // Set focus painted false
        // This removes border around
        // the label of JRadioButton
        // By default it is true
        r1.setFocusPainted(false);
        r4.setFocusPainted(false);
       
        // Set border painted true
        // Default it is false
        r4.setBorderPainted(true);
       
        // Set custom background
        r4.setBackground(Color.DARK_GRAY);
       
        // Set custom foreground
        r4.setForeground(Color.WHITE);
       
        // Set border
        r4.setBorder(BorderFactory.createEmptyBorder(5,10,5,10));
       
        // Now if you set roll over icon
        // to r4 it wont get displayed
        r4.setRolloverIcon(i3);
       
        // Even the roll over selected icon
        // will not work
        r4.setRolloverSelectedIcon(i5);
       
        // Set roll over enabled false
        r4.setRolloverEnabled(false);
       
        // Note:
        // If the above two statements' positions
        // are inter changed then there will be no
        // effect of the method setRolloverEnabled(false)
        // The methods setRolloverIcon() and setRolloverSelectedIcon()
        // internally call setRolloverEnabled(true);
       
        // Set hand cursor for JRadioButton
        r1.setCursor(new Cursor(Cursor.HAND_CURSOR));
       
        r3.setEnabled(true);
       
        // r1 will come selected
        // But the status label will not
        // show 'RadioButton 1 is selected'
        // since the most recent change when
        // the frame is opened will be r8.setSelected(false);
        r1.setSelected(true);
       
        // Add JRadioButtons to the ButtonGroup
        // The use of adding JRadioButtons to a
        // ButtonGroup is that, only one radio button
        // can be selected in a ButtonGroup of several
        // JRadioButtons i.e. if one is selected all others
        // in the same ButtonGroup remain deselected automatically.
       
        bg.add(r1);
        bg.add(r2);
    //    bg.add(r3);
        bg.add(r4);
        bg.add(r5);
        bg.add(r6);
        bg.add(r7);   
        bg.add(r8);
       
        // All the radio buttons in the ButtonGroup
        // become unselected after they were added to
        // ButtonGroup 'if and only if' they were
        // selected previously.
       
        // If you remove bg.add(r8); then the status
        // label will show 'Radio Button 6 is deselected'
        // since the setSelected(false) will only be fired
        // in the add() in ButtonGroup when the JRadioButton
        // is previously selected. Here r7 is not previously
        // selected. But r6 is.
       
        // Print the no.of buttons in the ButtonGroup bg
        System.out.println("No. of buttons in the ButtonGroup "+bg.getButtonCount());

       
        // Select r3
        // If r3 is not in the
        // ButtonGroup, selecting it
        // will not alter selection of
        // any other JRadioButton
        // in the group, since it has no
        // relation with the ButtonGroup
       
        // If r3 is in the ButtonGroup
        // and selected, then r3 will be
        // considered as the most recent selected
        // item though it was disabled   
        r3.setSelected(true);

       
        // Add all JRadioButtons
        p.add(r1);
        p.add(r2);
        p.add(r3);
        p.add(r4);
        p.add(r5);
        p.add(r6);
        p.add(r7);
        p.add(r8);
       
        // Add the panel, label
        add(p);
        add(label,BorderLayout.SOUTH);
       
        // Pack the JFrame
        // Pack after adding everything   
        pack();
       
        // Center the JFrame
        setLocationRelativeTo(null);
    }
   
    public static void main(String args[])
    {
        SwingUtilities.invokeLater(new Runnable(){
            public void run()
            {
                new JRadioButtonExample();
            }
        });
    }
}

Screenshot of JRadioButton Example
 


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Tags: Swing Components,