получить выбранный список переключателей в качели

Создайте QuestionAnswerPane, способный ссылаться на модель Question.

Эта панель будет отвечать за создание представления, представленного моделью Question, и сохранение в нем ответа пользователя.

QuestionAnswerPane должен знать, какой JRadioButton принадлежит какому answer. Когда пользователь выбирает один из переключателей, он обновляет модель Question ответом, который выбрал пользователь.

Когда пользователь нажимает Submit, вы просто просматриваете каждый Question и получаете ответ, выбранный пользователем.

Это также отделяет модель от пользовательского интерфейса, что упрощает работу с ней. С этой идеей вы могли бы проверить, например, на все ли вопросы были даны ответы. Этого также можно добиться, добавив в модель что-то вроде ChangeListener.

Обновлено с помощью примера BASIC

Это всего лишь пример, предназначенный для демонстрации концепции Question как централизованного контроллера/модели.

Что, судя по снимку экрана выше, выводит...

The color of a banana?
          Your answer was : Yellow
    The correct answer is : Yellow
                  You are : Right
The utimate question of life the universe and every thing?
          Your answer was : Choclate
    The correct answer is : 42
                  You are : Wrong
Who's your daddy?
          Your answer was : R2D2
    The correct answer is : Darth Vadar
                  You are : Wrong

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import javax.swing.AbstractAction;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.TitledBorder;

public class QuestionAnswer {

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

    public QuestionAnswer() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new QuestionsPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class QuestionsPane extends JPanel {

        public QuestionsPane() {

            setLayout(new GridBagLayout());
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridwidth = GridBagConstraints.REMAINDER;
            gbc.anchor = GridBagConstraints.WEST;
            gbc.weightx = 1;
            gbc.fill = GridBagConstraints.HORIZONTAL;

            final List<Question> questions = new ArrayList<>(3);
            questions.add(new Question("The color of a banana?", 
                            new Answer("Yellow"),
                            new Answer("Pink"),
                            new Answer("Blue"),
                            new Answer("Orange")
                    ));
            questions.add(new Question("The utimate question of life the universe and every thing?", 
                            new Answer("42"),
                            new Answer("Sleep"),
                            new Answer("Choclate"),
                            new Answer("1024"),
                            new Answer("Microsoft"),
                            new Answer("Apple")
                    ));
            questions.add(new Question("Who's your daddy?", 
                            new Answer("Darth Vadar"),
                            new Answer("Anikin Skywalker"),
                            new Answer("Yoda"),
                            new Answer("Mace Windo"),
                            new Answer("Chewbacca"),
                            new Answer("R2D2")
                    ));

            for (Question q : questions) {

                add(new QuestionAnswerPane(q), gbc);

            }

            gbc.weighty = 1;
            add(new JPanel(), gbc);
            gbc.weighty = 0;
            gbc.fill = GridBagConstraints.NONE;
            gbc.anchor = GridBagConstraints.CENTER;

            JButton submit = new JButton("Submit");
            submit.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    for (Question q : questions) {
                        System.out.println(q.getText());
                        System.out.println("\t      Your answer was : " + q.getSelectedAnswer());
                        System.out.println("\tThe correct answer is : " + q.getCorrectAnswer());
                        System.out.println("\t              You are : " + (q.isCorrectAnswer() ? "Right" : "Wrong"));
                    }
                }
            });

            add(submit, gbc);

        }

    }

    public class QuestionAnswerPane extends JPanel {

        public QuestionAnswerPane(Question question) {

            List<Answer> answers = new ArrayList<>(question.getWrongAnswers());
            answers.add(question.getCorrectAnswer());

            Collections.shuffle(answers);

            setBorder(new TitledBorder(question.getText()));
            setLayout(new GridBagLayout());
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridwidth = GridBagConstraints.REMAINDER;
            gbc.anchor = GridBagConstraints.WEST;
            gbc.weightx = 1;
            gbc.fill = GridBagConstraints.HORIZONTAL;

            ButtonGroup bg = new ButtonGroup();
            for (Answer answer : answers) {

                JRadioButton rb = new JRadioButton(new AnswerAction(question, answer));
                bg.add(rb);
                add(rb, gbc);

            }
            gbc.weighty = 1;
            add(new JPanel(), gbc);

        }

    }

    public class AnswerAction extends AbstractAction {

        private final Question question;
        private final Answer answer;

        public AnswerAction(Question question, Answer answer) {
            this.question = question;
            this.answer = answer;
            putValue(NAME, answer.getText());
        }

        public Answer getAnswer() {
            return answer;
        }

        public Question getQuestion() {
            return question;
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            getQuestion().setSelectedAnswer(answer);
        }

    }

    public class Question {

        private Answer correctAnswer;
        private List<Answer> wrongAnswers;
        private Answer selectedAnswer;

        private String text;

        public Question(String text, Answer correct, Answer... wrong) {
            wrongAnswers = new ArrayList<>(Arrays.asList(wrong));
            correctAnswer = correct;
            this.text = text;
        }

        public String getText() {
            return text;
        }

        public Answer getCorrectAnswer() {
            return correctAnswer;
        }

        public List<Answer> getWrongAnswers() {
            return Collections.unmodifiableList(wrongAnswers);
        }

        public Answer getSelectedAnswer() {
            return selectedAnswer;
        }

        public void setSelectedAnswer(Answer selectedAnswer) {
            this.selectedAnswer = selectedAnswer;
        }

        public boolean isCorrectAnswer() {
            Answer answer = getSelectedAnswer();
            Answer correct = getCorrectAnswer();
            return correct.equals(answer);
        }

        @Override
        public String toString() {
            return getText();
        }

    }

    public class Answer {

        private String text;

        public Answer(String text) {
            this.text = text;
        }

        public String getText() {
            return text;
        }

        @Override
        public String toString() {
            return getText();
        }

    }

}