TextEditor被修改时的事件怎么办

......import org.eclipse.ui.editors.text.TextEditor;import javax.swing.event.DocumentEvent;import javax.swing.event.DocumentListener;......public class test(){private TextEditor editor;......editor.getDocumentProvider().getDocument(editor.getEditorInput())        .addDocumentListener(new DocumentListener(){    @Override    public void changedUpdate(DocumentEvent arg0) {    // TODO Auto-generated method stub                                    }    @Override    public void insertUpdate(DocumentEvent arg0) {    // TODO Auto-generated method stub                                    }    @Override    public void removeUpdate(DocumentEvent arg0) {    // TODO Auto-generated method stub                                    }                             });.......}