code: public void actionUndoChanges() throws JspException {
  
          // save initialized instance of this class in request attribute for included sub-elements
          getJsp().getRequest().setAttribute(SESSION_WORKPLACE_CLASS, this);
          try {
              boolean isFolder = false;
              String source = getResourceList().get(0);
              if (!isMultiOperation()) {
                  CmsResource resource = getCms().readResource(source, CmsResourceFilter.ALL);
                  isFolder = resource.isFolder();
              }
              // get the folders to refresh
              List<String> folderList = new ArrayList<String>(1 + getResourceList().size());
              folderList.add(CmsResource.getParentFolder(source));
              Iterator<String> it = getResourceList().iterator();
              while (it.hasNext()) {
                  String res = it.next();
                  String target = resourceOriginalPath(getCms(), res);
                  if ((target != null) && !target.equals(res)) {
                      CmsResource resource = getCms().readResource(res, CmsResourceFilter.ALL);
                      if (resource.isFolder()) {
                          folderList.add(CmsResource.getParentFolder(target));
                      }
                  }
              }
              if (performDialogOperation()) {
                  // if no exception is caused and "true" is returned move operation was successful
                  if (isMultiOperation() || isFolder) {
                      // set request attribute to reload the explorer tree view
                      getJsp().getRequest().setAttribute(REQUEST_ATTRIBUTE_RELOADTREE, folderList);
                  }
                  actionCloseDialog();
              } else {
                  // "false" returned, display "please wait" screen
                  getJsp().include(FILE_DIALOG_SCREEN_WAIT);
              }
          } catch (Throwable e) {
              // error during deletion, show error dialog
              includeErrorpage(this, e);
          }
      }
docs: Performs the undo changes action, will be called by the JSP page.<p>
  
  @throws JspException if problems including sub-elements occur