.orElseThrow(() -> new FessSystemException("Cannot create an access token."));
    }

    public void saveToken() {
        getSessionManager().setAttribute(Constants.SEARCH_ENGINE_API_ACCESS_TOKEN, UUID.randomUUID().toString().replace("-", ""));
    }

    private SessionManager getSessionManager() {

    }

    @Override
    protected String getActionRole() {
        return ROLE;
    }

    @Execute
    @Secured({ ROLE, ROLE + VIEW })
    public HtmlResponse index() {
        saveToken();
        return asListHtml();
    }

    @Execute
    @Secured({ ROLE })
    public HtmlResponse upload(final UploadForm form) {
        validate(form, messages -> {}, this::asListHtml);

    //                                                                      ==============

    @Execute
    @Secured({ ROLE, ROLE + VIEW })
    public HtmlResponse index() {
        saveToken();
        return asIndexHtml();
    }

    private HtmlResponse asIndexHtml() {
        return asHtml(path_AdminMaintenance_AdminMaintenanceJsp).useForm(ActionForm.class, op -> op.setup(f -> {

    //                                                                      ==============

    @Execute
    @Secured({ ROLE, ROLE + VIEW })
    public HtmlResponse index() {
        saveToken();
        return asIndexHtml();
    }

    private HtmlResponse asIndexHtml() {
        return asHtml(path_AdminUpgrade_AdminUpgradeJsp).useForm(UpgradeForm.class);
    }

    @Execute