* @param value the value to validate
     * @return true if valid, false otherwise
     */
    protected boolean determineValid(final String value) {
        if (StringUtil.isNotBlank(value) && !LaCronUtil.isCronExpValid(value)) {
            return false;
        }
        return true;
    }

     * @param attrName the attribute name to extract URLs from
     */
    public void addChildUrlRule(final String tagName, final String attrName) {
        if (StringUtil.isNotBlank(tagName) && StringUtil.isNotBlank(attrName)) {
            childUrlRuleMap.put(tagName, attrName);
        }
    }

    /**
     * Gets the XPath API instance for this thread.
     *
     * @return the XPath API instance

                searchLogHelper.addClickLog(clickLog);
            }
        }

        final String targetUrl = pathMappingHelper.replaceUrl(url);

        String hash;
        if (StringUtil.isNotBlank(form.hash)) {
            final String value = URLUtil.decode(form.hash, Constants.UTF_8);
            if (targetUrl.indexOf('#') == -1) {
                final StringBuilder buf = new StringBuilder(value.length() + 100);

        }
        if (client == null) {
            throw new CrawlerSystemException("CrawlerClient is null.");
        }
        for (final String regex : regexList) {
            if (StringUtil.isNotBlank(regex)) {
                clientMap.put(Pattern.compile(regex), client);
            }
        }
    }

    /**
     * Retrieves a client that matches the given URL key.

                final Node classAttr = node.getAttributes().getNamedItem("class");
                if (classAttr != null) {
                    final String value = classAttr.getNodeValue();
                    if (StringUtil.isNotBlank(value)) {
                        return StreamUtil.split(value, " ").get(stream -> stream.anyMatch(s -> css.equals(s)));
                    }
                }
            } else {

                .filter(StringUtil::isNotBlank)
                .distinct()
                .collect(Collectors.joining("\n")));
        body.virtualHosts = stream(entity.getVirtualHosts())
                .get(stream -> stream.filter(StringUtil::isNotBlank).distinct().map(String::trim).collect(Collectors.joining("\n")));
        return body;
    }

        final String redirectUrl = userBean.map(user -> ComponentUtil.getSsoManager().logout(user)).orElse(null);
        fessLoginAssist.logout();
        userInfoHelper.deleteUserCodeFromCookie(request);
        if (StringUtil.isNotBlank(redirectUrl)) {
            return HtmlResponse.fromRedirectPathAsIs(redirectUrl);
        }
        return redirect(LoginAction.class);
    }

     */
    @Override
    public String getDataAsString() {
        if (data == null) {
            return null;
        }
        try {
            return new String(data, StringUtil.isNotBlank(encoding) ? encoding : Constants.UTF_8);
        } catch (final UnsupportedEncodingException e) {
            return new String(data, Constants.UTF_8_CHARSET);
        }
    }

    /**

            form.permissions = stream(entity.getPermissions()).get(stream -> stream.map(s -> permissionHelper.decode(s))
                    .filter(StringUtil::isNotBlank)
                    .distinct()
                    .collect(Collectors.joining("\n")));
        }).orElse(() -> {

                    final Map<String, Object> doc = hit.getSourceAsMap();
                    final String url = DocumentUtil.getValue(doc, fessConfig.getIndexFieldUrl(), String.class);
                    if (StringUtil.isNotBlank(url)) {
                        final Set<String> labelSet = labelTypeHelper.getMatchedLabelValueSet(url);
                        final Script script = languageHelper.createScript(doc, "ctx._source." + fessConfig.getIndexFieldLabel()