JAVA GUI : Test Radio Buttton

// paket yang diperlukan
import javax.swing.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

class TestRButton extends JFrame{
    // attribut
    //membuat tombol
    JButton tombol1 = new JButton("cek ?");
    JButton tombol2 = new JButton("set nilai true");
    JLabel label = new JLabel("nilai check box");
    // JRadioButton(String nama)
    JRadioButton cb = new JRadioButton("Makan");
    JRadioButton cb2 = new JRadioButton("Ayam");
    JRadioButton cb3 = new JRadioButton("goreng");
    ButtonGroup group = new ButtonGroup();

    //konstruktor
    public TestRButton(){
        //frame seting---------------------------------------------------------------------
        //memanggil konstruktor kelas induk (JFrame)
        super("Contoh Tombol");
        //seting besar frame 400 x 400 px
        this.setSize(200,250);
        //seting agar bisa ditutup
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);
        //seting kemunculan frame di tengah window
        this.setLocationRelativeTo(null);
        //seting layout frame
        this.getContentPane().setLayout(null);
        //frame seting---------------------------------------------------------------------
        //menambahkan komponen ke frame dan seting letak
        this.add(tombol1);
        this.add(tombol2);
        this.add(label);
        this.add(cb);
        this.add(cb2);
        this.add(cb3);
        // setbounds(x,y,lebar,tinggi)
        tombol1.setBounds(10,10,150,25);
        tombol2.setBounds(10,40,150,25);
        label.setBounds(10,70,150,25);
        cb.setBounds(10,110,150,25);
        cb2.setBounds(10,140,150,25);
        cb3.setBounds(10,170,150,25);
        //seting aksi tombol
        group.add(cb);
        group.add(cb2);
        group.add(cb3);
        tombol1.addActionListener(new ActionListener( ) {
            public void actionPerformed(ActionEvent e){
                // kode disini; cek keadaan check box
                if(cb.isSelected()) label.setText("Makan");
                if(cb2.isSelected()) label.setText("Ayam");
                if(cb3.isSelected()) label.setText("Goreng");
            }
        });
        tombol2.addActionListener(new ActionListener( ) {
            public void actionPerformed(ActionEvent e){
                // kode disini; cek keadaan check box ganti keadaan chek box
                if(cb.isSelected()) cb2.setSelected(true);
                else if(cb2.isSelected()) cb3.setSelected(true);
                else if(cb3.isSelected()) cb.setSelected(true);
            }
        });
        // menampilkan frame
        show();

    }

    public static void main(String[] args){
        new TestRButton();
    }
}