Select Radio Button,Selection Radio Button in Java,Radio Button Selection Component in Java

Selecting a Radio Button component in Java

In this section, you will learn how to set the radio buttons in a group so that only one can be selected at a time.

This program shows five radio buttons with labeled by "First", "Second", "Third", "Fourth" and "Fifth". This program also show a label which contains the text "Roseindia.net" but when you click on any radio button from a ButtonGroup the text of the selected radio button is shown on the label and a message box will be shown with message holds the selected radio button label. This is done through the generating event for the different-different radio buttons. Following are the screen shots for the result of the given program:

Frame with a message dialog box when you select the second radio button

For this purposes, there are some APIs or methods have been used as follows:

getActionCommand():
This is the method of the ActionEvent class which returns the source title in string of the generated event.

Here is the code of the program:


import javax.swing.*;

import java.awt.*;

import java.awt.event.*;



public class SelectRadioButton{

  JLabel label;

  public static void main(String[] args){

    SelectRadioButton sr = new SelectRadioButton();

  }



  public SelectRadioButton(){

    JFrame frame = new JFrame("Radio button selection");

    JRadioButton first = new JRadioButton("First");

    JRadioButton second = new JRadioButton("Second");

    JRadioButton third = new JRadioButton("Third");

    JRadioButton fourth = new JRadioButton("Fourth");

    JRadioButton fifth = new JRadioButton("Fifth");

    JPanel panel = new JPanel();

    panel.add(first);

    panel.add(second);

    panel.add(third);

    panel.add(fourth);

    panel.add(fifth);

    ButtonGroup bg = new ButtonGroup();

    bg.add(first);

    bg.add(second);

    bg.add(third);

    bg.add(fourth);

    bg.add(fifth);

    first.addActionListener(new MyAction());

    second.addActionListener(new MyAction());

    third.addActionListener(new MyAction());

    fourth.addActionListener(new MyAction());

    fifth.addActionListener(new MyAction());

    label = new JLabel("Roseindia.net");

    frame.add(panel, BorderLayout.NORTH);

    frame.add(label, BorderLayout.CENTER);

    frame.setSize(400, 400);

    frame.setVisible(true);

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

  }



  public class MyAction implements ActionListener{

    public void actionPerformed(ActionEvent e){

      label.setText(e.getActionCommand());

      JOptionPane.showMessageDialog(null,"This is the " + e.getActionCommand() + 

" radio button.");

    }

  }

}