Java JRadioButton

Java JRadioButton

JRadioButton is used to create radio button.JRadioButtons are used to select one option from several options unlike JCheckBox that you can select multiple options.
A group of radio buttons should be added to one ButtonGroup in order to select one.

How to Declare JRadioButton class

This is how you declare javax.swing.JRadioButton.

[public class JRadioButton extends JToggleButton implements Accessible]

Constructors used in JRadioButton.

• JRadioButton()-creates radio button that is unselected.
• JRadioButton(String s)-creates radio button with a certain text.
• JRadioButton(String s,boolean selected)-creates radio button that is selected and with a certain text.

JRadioButtons commonly used methods.

• void setText(String s)-used to specify radio button text.
• String getText()-returns radio button text.
• void setEnabled(boolean value)-used to enable or disable the button.
• void  setIcon(Icon icon)-used to add icon to the radio button.
• Icon getIcon()-returns icon used in the radio button.
• void setMnemonic(int a)-use to set radio button mnemonic.
• void addActionListener(ActionListener l)-used to add actionlistener. 

Java JRadioButton Example

[

import javax.swing.JRadioButton;
import javax.swing.ButtonGroup;
import javax.swing.JFrame;
public class RadioButtonExample extends JFrame {

    RadioButtonExample()
    {
        super("JRadioButton Example");

        JRadioButton button1=new JRadioButton("A) Male");
        JRadioButton button2=new JRadioButton("B) Female");
        button1.setBounds(75,50,100,30);
        button2.setBounds(75,100,100,30);
        ButtonGroup bg=new ButtonGroup();
        bg.add(button1);bg.add(button2);
        add(button1);
        add(button2);

        setLocationRelativeTo(null);
        setSize(400,400);
        setLayout(null);
        setVisible(true);
    }
    public static void main(String args[])
    {
        new RadioButtonExample();
    }

}

]

Output:

Java JRadioButton Example with ActionListener

[

import javax.swing.JRadioButton;
import javax.swing.ButtonGroup;
import javax.swing.JFrame;
import javax.swing.JButton;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JOptionPane;
public class RadioButtonExample extends JFrame implements ActionListener{
    public JRadioButton button1,button2;
    public JButton save;

    RadioButtonExample()
    {
        super("JRadioButton Example");
        button1=new JRadioButton("A) Male");
        button2=new JRadioButton("B) Female");
        button1.setBounds(75,50,100,30);
        button2.setBounds(75,100,100,30);
        ButtonGroup bg=new ButtonGroup();
        bg.add(button1);bg.add(button2);
        add(button1);
        add(button2);

        save=new JButton("Save");
        save.setBounds(75,150,100,30);
        add(save);
        save.addActionListener(this);

        setLocationRelativeTo(null);
        setSize(400,400);
        setLayout(null);
        setVisible(true);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }

    public void actionPerformed(ActionEvent event)
    {
        if(button1.isSelected())
        {
            JOptionPane.showMessageDialog(this, "You Gender is Male",
                    "JRadioButton Example",JOptionPane.INFORMATION_MESSAGE);
        }
        if(button2.isSelected())
        {
            JOptionPane.showMessageDialog(this, "You Gender is Female",
                    "JRadioButton Example",JOptionPane.INFORMATION_MESSAGE);
        }
    }
    public static void main(String args[])
    {
        new RadioButtonExample();
    }
}

]

Output

Code Explanation:

Above program introduces several java.swing class components These are :-

• JButton
• JOptionPane:showMessageDialog 

The program extends class JFrame and implements ActionListener interface.

Note:Once you extends a class,you can be able to access all the class methods.

JFrame methods include setSize,setLayout,setDefaultCloseOperation etc.

If a class is not abstract and it implements a certain interface,you are required to override all interface abstract methods.

Code [button1.isSelected()] checks if the radio button is selected.

Next Topic:Java JComboBox