Java by API/javax.swing/ButtonGroup

ButtonGroup: add(AbstractButton b)

 
import javax.swing.ButtonGroup;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
public class MainClass extends JPanel {
  public MainClass() {
    JRadioButton radMarriedYes = new JRadioButton("Yes?", true);
    JRadioButton radMarriedNo = new JRadioButton("No?", false);
    JRadioButton radGolfYes = new JRadioButton("Yes?", false);
    JRadioButton radGolfNo = new JRadioButton("No?", true);
    ButtonGroup radioGroup1 = new ButtonGroup();
    ButtonGroup radioGroup2 = new ButtonGroup();
    setLayout(null);
    add(radMarriedYes);
    add(radMarriedNo);
    add(radGolfYes);
    add(radGolfNo);
    radioGroup1.add(radMarriedYes);
    radioGroup1.add(radMarriedNo);
    radioGroup2.add(radGolfYes);
    radioGroup2.add(radGolfNo);
    radMarriedYes.setBounds(30, 50, 50, 20);
    radMarriedNo.setBounds(30, 80, 50, 20);
    radGolfYes.setBounds(150, 50, 50, 20);
    radGolfNo.setBounds(150, 80, 50, 20);
  }
  public static void main(String[] args) {
    JFrame frame = new JFrame();
    frame.getContentPane().add(new MainClass());
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(200, 200);
    frame.setVisible(true);
  }
}

ButtonGroup: getSelection()

 
import java.awt.Container;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.AbstractButton;
import javax.swing.ButtonGroup;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JRadioButton;
public class MainClass {
  public static void main(String[] args) {
    JRadioButton dem = new JRadioButton("Bill", false);
    dem.setActionCommand("Bill");
    JRadioButton rep = new JRadioButton("Bob", false);
    rep.setActionCommand("Bob");
    JRadioButton ind = new JRadioButton("Ross", false);
    ind.setActionCommand("Ross");
    final ButtonGroup group = new ButtonGroup();
    group.add(dem);
    group.add(rep);
    group.add(ind);
    class VoteActionListener implements ActionListener {
      public void actionPerformed(ActionEvent ex) {
        String choice = group.getSelection().getActionCommand();
        System.out.println("ACTION Candidate Selected: " + choice);
      }
    }
    class VoteItemListener implements ItemListener {
      public void itemStateChanged(ItemEvent ex) {
        String item = ((AbstractButton) ex.getItemSelectable()).getActionCommand();
        boolean selected = (ex.getStateChange() == ItemEvent.SELECTED);
        System.out.println("ITEM Candidate Selected: " + selected + " Selection: " + item);
      }
    }
    ActionListener al = new VoteActionListener();
    dem.addActionListener(al);
    rep.addActionListener(al);
    ind.addActionListener(al);
    ItemListener il = new VoteItemListener();
    dem.addItemListener(il);
    rep.addItemListener(il);
    ind.addItemListener(il);
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container c = frame.getContentPane();
    c.setLayout(new GridLayout(4, 1));
    c.add(new JLabel("Please Cast Your Vote"));
    c.add(dem);
    c.add(rep);
    c.add(ind);
    frame.pack();
    frame.setVisible(true);
  }
}

ButtonGroup: setSelected(ButtonModel m, boolean b)

  
import javax.swing.ButtonGroup;
import javax.swing.ButtonModel;
import javax.swing.JRadioButton;
public class Main {
  public static void main(String[] argv) throws Exception {
    JRadioButton radioButton = new JRadioButton();
    ButtonGroup group = new ButtonGroup();
    ButtonModel model = radioButton.getModel();
    group.setSelected(model, true);
  }
}