JTextArea.getText returning null values

Question

I'm doing a flashcards program and I cannot save cards because my .getText method is returning null values and I cannot figure out why:

package eFlashcards;
//lot of imports

public class QuizCardBuilder {
    
    private JTextArea question;
    private JTextArea answer;
    private ArrayList<QuizCard> cardList;
    private JFrame frame;
    
    public static void main(String[] args) {
        QuizCardBuilder builder = new QuizCardBuilder();
        builder.go();
    }
    
    public void go() {
        frame = new JFrame("Quiz Card Builder");
        JPanel mainPanel = new JPanel();
        Font bigFont = new Font("sanserif", Font.BOLD, 24);
        
        question = new JTextArea(6,20);
        question.setLineWrap(true);
        question.setWrapStyleWord(true);
        question.setFont(bigFont);
        
        JScrollPane qScroller = new JScrollPane(question);
        qScroller.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
        qScroller.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
        
        answer = new JTextArea(6,20);
        answer.setLineWrap(true);
        answer.setWrapStyleWord(true);
        answer.setFont(bigFont);
        
        JScrollPane aScroller = new JScrollPane(answer);
        aScroller.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
        aScroller.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
        
        JButton nextButton = new JButton("Next card");
        cardList = new ArrayList<QuizCard>();
        JLabel qLabel = new JLabel("Question:");
        JLabel aLabel = new JLabel("Answer:");
        
        mainPanel.add(qLabel);
        mainPanel.add(qScroller);
        mainPanel.add(aLabel);
        mainPanel.add(aScroller);
        mainPanel.add(nextButton);
        nextButton.addActionListener(new NextCardListener());
        JMenuBar menuBar = new JMenuBar();
        JMenu fileMenu = new JMenu("File");
        JMenuItem newMenuItem = new JMenuItem("New");
        JMenuItem saveMenuItem = new JMenuItem("Save");
        newMenuItem.addActionListener(new NewMenuListener());
        saveMenuItem.addActionListener(new SaveMenuListener());
        fileMenu.add(newMenuItem);
        fileMenu.add(saveMenuItem);
        menuBar.add(fileMenu);
        frame.setJMenuBar(menuBar);
        frame.add(BorderLayout.CENTER,mainPanel);
        frame.setSize(500,600);
        frame.setVisible(true);
    }
    
    private class NextCardListener implements ActionListener {
        public void actionPerformed(ActionEvent ev) {
            QuizCard card = new QuizCard(question.getText(),answer.getText());
            System.out.println(question);
            System.out.println(answer);
            cardList.add(card);
            clearCard();
        }
    }
    
    private class SaveMenuListener implements ActionListener {
        public void actionPerformed(ActionEvent ev) {
            QuizCard card = new QuizCard(question.getText(),answer.getText());
            cardList.add(card);
            JFileChooser fileSave = new JFileChooser();
            fileSave.showSaveDialog(frame);
            saveFile(fileSave.getSelectedFile());
        }
    }

    private class NewMenuListener implements ActionListener {
        public void actionPerformed(ActionEvent ev) {
            cardList.clear();
            clearCard();
        }
    }
    
    private void saveFile(File file) {
        try {
            BufferedWriter writer = new BufferedWriter(new FileWriter(file));
            
            for(QuizCard card:cardList) {
                writer.write(card.getQuestion() + "/");
                writer.write(card.getAnswer() + "\n");
            }
            writer.close();
        } catch(IOException ex) {
            System.out.println("Couldn't write the cardList out");
            ex.printStackTrace();
        }
    }
        
        
    

    public void clearCard() {
        question.setText("");
        answer.setText("");
        question.requestFocus();
        
    }
}

package eFlashcards;


public class QuizCard {
public String question;
public String answer;

public QuizCard(String q, String a) {
    q = question;
    a = answer;
} 

public String getQuestion() {
    return question;
}

public String getAnswer() {
    return answer;
}

}

Let me know if more code is needed to understand the problem. I tried debugging, turns out the question and answer variables when I create a new QuizCard object are null by the time of saving...

Answer 1

Your QuizCard constructor assigns in the wrong direction. It assigns the fields to the parameters. Prevent this in the future by declaring the parameters as final:

public QuizCard(final String q, final String a) {
    question = q;
    answer = a;
}