Radio Button

import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;

public class RadioGUI extends JFrame {
    ButtonGroup group = new ButtonGroup();
    private JTextArea textArea1;
    private JPanel panelMain;
    private JCheckBox checkBox1;
    private JRadioButton povinnéRadioButton;
    private JRadioButton nepovinnéRadioButton;
    private JButton pridejButton;



    public RadioGUI() {
        group.add(povinnéRadioButton);
        group.add(nepovinnéRadioButton);

        pridejButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                textArea1.append(String.valueOf(LocalDate.now()+ " " + LocalTime.now()+" "));
                if(checkBox1.isSelected()){
                    textArea1.append("Splněno");
                }
                else {
                    textArea1.append("Nesplněno");
                }
                if(povinnéRadioButton.isSelected()){
                    textArea1.append("(povinné)\n");
                }
                else{
                    textArea1.append("(nepovinné)\n");
                }
            }
        });
    }

    public static void main(String[] args) {
        RadioGUI gui = new RadioGUI();
        gui.setVisible(true);
        gui.setContentPane(gui.panelMain);
        gui.setTitle("úkoly");
        gui.setSize(800, 450);
        gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    }
}