code: public void exportDataSetExcel(final DataSetLookup request,
                                     final DataSetExportReadyCallback listener) throws Exception {
  
          if (dataSetLookupServices != null) {
              // Look always into the client data set manager.
              if (clientDataSetManager.getDataSet(request.getDataSetUUID()) != null) {
                  DataSet dataSet = clientDataSetManager.lookupDataSet(request);
                  try {
                      dataSetExportServices.call(
                              new RemoteCallback<Path>() {
                                  public void callback(Path excelFilePath) {
                                      listener.exportReady(excelFilePath);
                                  }
                              }).exportDataSetExcel(dataSet);
                  } catch (Exception e) {
                      throw new RuntimeException(e);
                  }
              }
              // Data set not found on client.
              else {
                  // If the data set is not in client, then look up remotely (only if the remote access is available).
                  try {
                      dataSetExportServices.call(
                              new RemoteCallback<Path>() {
                                  public void callback(Path excelFilePath) {
                                      listener.exportReady(excelFilePath);
                                  }
                              }
                              ,
                              new ErrorCallback<Message>() {
                                  public boolean error(Message message,
                                                       Throwable throwable) {
                                      listener.onError(new ClientRuntimeError(throwable));
                                      return true;
                                  }
                              }).exportDataSetExcel(request);
                  } catch (Exception e) {
                      listener.onError(new ClientRuntimeError(e));
                  }
              }
          } else {
              listener.onError(new ClientRuntimeError(CommonConstants.INSTANCE.exc_no_client_side_data_export()));
          }
      }
docs: Export a data set, specified by a data set lookup request, to Excel format.
  
  @param request The data set lookup request
  @throws Exception It there is an unexpected error during the export.