Using undo and redo for JTextArea

Question

I am making a text editor using Java swing. I am using JTextArea for the same. I want to know how I can use Undo and Redo functionality in JTextArea as I am not able to use

Answer 1

I had to go through multiple links just to get enough help. I'm adding here what I implemented successfully just to help future visitors. I implemented this using JTextPane but am assuming the same would apply for the JTextArea

    JTextArea textArea = new JTextArea();
    JButton undo = new JButton("Undo");
    JButton redo = new JButton("Redo");
    KeyStroke undoKeyStroke = KeyStroke.getKeyStroke(
            KeyEvent.VK_Z, Event.CTRL_MASK);
    KeyStroke redoKeyStroke = KeyStroke.getKeyStroke(
            KeyEvent.VK_Y, Event.CTRL_MASK);

    UndoManager undoManager = new UndoManager();

    Document document = textArea.getDocument();
    document.addUndoableEditListener(new UndoableEditListener() {
        @Override
        public void undoableEditHappened(UndoableEditEvent e) {
            undoManager.addEdit(e.getEdit());
        }
    });

    // Add ActionListeners
    undo.addActionListener((ActionEvent e) -> {
        try {
            undoManager.undo();
        } catch (CannotUndoException cue) {}
    });
    redo.addActionListener((ActionEvent e) -> {
        try {
            undoManager.redo();
        } catch (CannotRedoException cre) {}
    });

    // Map undo action
    textArea.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW)
            .put(undoKeyStroke, "undoKeyStroke");
    textArea.getActionMap().put("undoKeyStroke", new AbstractAction() {
        @Override
        public void actionPerformed(ActionEvent e) {
            try {
                undoManager.undo();
             } catch (CannotUndoException cue) {}
        }
    });
    // Map redo action
    textArea.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW)
            .put(redoKeyStroke, "redoKeyStroke");
    textArea.getActionMap().put("redoKeyStroke", new AbstractAction() {
        @Override
        public void actionPerformed(ActionEvent e) {
            try {
                undoManager.redo();
             } catch (CannotRedoException cre) {}
        }
    });