用java实现编辑器的Undo Redo功能，非常的方便，下面是一个实现这个功能的类，import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JEditorPane;
import javax.swing.KeyStroke;
import javax.swing.event.UndoableEditEvent;
import javax.swing.event.UndoableEditListener;
import javax.swing.text.JTextComponent;
import javax.swing.undo.CannotRedoException;
import javax.swing.undo.CannotUndoException;
import javax.swing.undo.UndoManager;
/**
* UndoWrapper is responsible for adding undo and redo support to text components.
* @author Antonio Vieiro (antonio@antonioshome.net), $Author: $
* @version $Revision: $
*/
public class UndoWrapper
　implements UndoableEditListener
{
　private UndoManager undoManager;
　private UndoAction undoAction;
　private RedoAction redoAction;
　private JEditorPane textComponent;
　　
　/**
　 * Creates a new instance of UndoWrapper
　 */
　public UndoWrapper( JEditorPane aComponent )
　{
　　textComponent = aComponent;
　　undoManager = new UndoManager();
　　undoAction = new UndoAction();
　　redoAction = new RedoAction();
　　textComponent.getDocument().addUndoableEditListener( this );
　　textComponent.getInputMap().put( (KeyStroke) undoAction.getValue(
Action.ACCELERATOR_KEY), "undo" );
　　textComponent.getInputMap().put( (KeyStroke) redoAction.getValue(
Action.ACCELERATOR_KEY), "redo" );
　　textComponent.getActionMap().put( "undo", undoAction );
　　textComponent.getActionMap().put( "redo", redoAction );
　}
　
　public void undoableEditHappened(UndoableEditEvent e)
　{
　　undoManager.addEdit( e.getEdit() );
　　undoAction.updateUndoState();
　　redoAction.updateRedoState();
　}
　
　/**
　 * UndoAction is the Action responsible for handling the undo operation.
　 */
　class UndoAction
　　extends AbstractAction
　{
　　public UndoAction()
　　{
　　　super( "Cannot undo" ); // TODO: I18N
　　　setEnabled( false );
　　　putValue( Action.ACCELERATOR_KEY, KeyStroke.getKeyStroke("ctrl Z") );
　　}
　　
　　public void actionPerformed(ActionEvent e)
　　{
　　　try
　　　{
　　　　undoManager.undo();
　　　}
　　　catch( CannotUndoException cue )
　　　{
　　　　// TODO: Use logging?
　　　　cue.printStackTrace( System.err );
　　　}
　　(编辑:aniston)