return response.isExists();
        } catch (final Exception e) {
            // ignore
        }
        return false;
    }

    public static void deleteIndex(final IndicesAdminClient indicesClient, final String index,
            final Consumer<AcknowledgedResponse> comsumer) {
        indicesClient.prepareDelete(index).execute(new ActionListener<AcknowledgedResponse>() {

                }
            }
        }
        for (final String index : crawlerIndices) {
            if (client.existsIndex(index)) {
                if (client.deleteIndex(index)) {
                    logger.warn("Deleted {}.", index);
                } else {
                    logger.warn("Failed to delete {}.", index);
                }

            }
        } catch (final Exception e) {
            logger.warn("{} is not found.", indexConfigFile, e);
        }

        return false;
    }

    public boolean deleteIndex(final String indexName) {
        final FessConfig fessConfig = ComponentUtil.getFessConfig();
        try {
            final AcknowledgedResponse response =