public String execute() throws Exception {
    String[] importItemIds = selectionManager.getListObject();

    if (importItemIds == null) {
      message = i18n.getString("choose_import_item");

      return ERROR;
    }

    OrganisationUnit organisationUnit =
        organisationUnitSelectionManager.getSelectedOrganisationUnit();

    if (organisationUnit != null) {
      Period period = periodGenericManager.getSelectedPeriod();

      Set<DataValue> oldDataValues = new HashSet<DataValue>();
      Set<DataValue> newDataValues = new HashSet<DataValue>();

      executeToImport(organisationUnit, period, importItemIds, oldDataValues, newDataValues);

      selectionManager.setOldDataValueList(oldDataValues);
      selectionManager.setNewDataValueList(newDataValues);
    }

    message = i18n.getString("import_successfully");

    return SUCCESS;
  }