Mine

import javax.swing.*;import java.awt.event.ActionListener;import java.awt.event.ActionEvent;public class Test extends JFrame {    public static void main(String[] args) {        Test app = new Test();        app.setVisible(true);    }    public Test() {        JButton radioWindowBtn = new JButton("Show Window");        radioWindowBtn.addActionListener(new ActionListener() {            public void actionPerformed(ActionEvent e) {                displayWindow();            }        });        getContentPane().add(radioWindowBtn);    }    protected void displayWindow() {        JFrame frame = new JFrame();        JRadioButton radioBtn = new JRadioButton("Testing");        radioBtn.addActionListener(new ActionListener() {            public void actionPerformed(ActionEvent e) {                if (((JRadioButton) e.getSource()).isSelected()) {                    System.out.println("Radio button is selected");                }            }        });        frame.getContentPane().add(radioBtn);        frame.setVisible(true);    }}