Java - JTextComponents Undo

import java.awt.event.ActionEvent;

import javax.swing.AbstractAction;
import javax.swing.KeyStroke;
import javax.swing.event.UndoableEditEvent;
import javax.swing.event.UndoableEditListener;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.JTextComponent;
import javax.swing.text.PlainDocument;
import javax.swing.undo.CompoundEdit;
import javax.swing.undo.UndoManager;

public class UndoComponentManager
{
    @SuppressWarnings("serial")
    public static void addTo(JTextComponent component)
    {
        // Add custom undo document
        component.setDocument(new PlainDocument()
        {
            private CompoundEdit compoundEdit;

            @Override
            public void replace(int offset, int length, String text,
                    AttributeSet attrs) throws BadLocationException
            {
                if (length == 0)
                {
                    super.replace(offset, length, text, attrs);
                } else
                {
                    compoundEdit = new CompoundEdit();

                    super.fireUndoableEditUpdate(new UndoableEditEvent(this,
                            compoundEdit));

                    super.replace(offset, length, text, attrs);

                    compoundEdit.end();
                }
            }
        });

        // Create UndoManager instance
        final UndoManager undoManager = new UndoManager();

        // Listen for edits on the component
        component.getDocument().addUndoableEditListener(
                new UndoableEditListener()
                {
                    public void undoableEditHappened(UndoableEditEvent evt)
                    {
                        undoManager.addEdit(evt.getEdit());
                    }
                });

        // Map CTRL + Y to redo action
        component.getActionMap().put("Undo", new AbstractAction("Undo")
        {
            public void actionPerformed(ActionEvent evt)
            {
                if (undoManager.canUndo())
                {
                    undoManager.undo();
                }
            }
        });
        component.getInputMap()
                .put(KeyStroke.getKeyStroke("control Z"), "Undo");

        // Map CTRL + Y to redo action
        component.getActionMap().put("Redo", new AbstractAction("Redo")
        {
            public void actionPerformed(ActionEvent evt)
            {
                if (undoManager.canRedo())
                {
                    undoManager.redo();
                }
            }
        });
        component.getInputMap()
                .put(KeyStroke.getKeyStroke("control Y"), "Redo");
    }
}