public ActionResponse download(final String id) {
        if (logger.isDebugEnabled()) {
            logger.debug("Backup download requested: id={}", id);
        }

        if (stream(fessConfig.getIndexBackupAllTargets()).get(stream -> stream.anyMatch(s -> s.equals(id)))) {
            if ("system.properties".equals(id)) {
                return asStream(id).contentTypeOctetStream().stream(out -> {

     */
    // GET /api/admin/backup/file/{id}
    @Execute
    public StreamResponse get$file(final String id) {
        final FessConfig fessConfig = ComponentUtil.getFessConfig();
        if (stream(fessConfig.getIndexBackupAllTargets()).get(stream -> stream.anyMatch(s -> s.equals(id)))) {
            if ("system.properties".equals(id)) {
                return asStream(id).contentTypeOctetStream().stream(out -> {

        return Constants.TRUE.equalsIgnoreCase(getIndexerThreadDumpEnabled());
    }

    String getIndexBackupTargets();

    String getIndexBackupLogTargets();

    default String[] getIndexBackupAllTargets() {
        return split(getIndexBackupTargets() + "," + getIndexBackupLogTargets(), ",")
                .get(stream -> stream.filter(StringUtil::isNotBlank).map(String::trim).toArray(n -> new String[n]));
    }