* Contains helper methods for string operations, including backported JDK functionality
 * for compatibility with older Java versions.
 */
public final class StringUtil {

    /**
     *
     */
    private StringUtil() {
    }

    /**
     * Implementation of {@link java.lang.String#join} backported for JDK7.
     *
     * @param delimiter the separator to use between elements

import org.junit.jupiter.params.provider.ValueSource;

/**
 * Test class for StringUtil utility methods
 */
class StringUtilTest {

    @Test
    @DisplayName("Should join single element without delimiter")
    void testJoinSingleElement() {
        String result = StringUtil.join(",", "hello");
        assertEquals("hello", result);
    }

    @Test

        final String slackWebhookUrls = fessConfig.getSlackWebhookUrls();
        if (StringUtil.isBlank(slackWebhookUrls)) {
            return;
        }
        final String body = toSlackMessage(discloser);
        StreamUtil.split(slackWebhookUrls, "[,\\s]").of(stream -> stream.filter(StringUtil::isNotBlank).forEach(url -> {

        final String value = ComponentUtil.getFessConfig().getSystemProperty("oic.default.groups");
        if (StringUtil.isBlank(value)) {
            return StringUtil.EMPTY_STRINGS;
        }
        return split(value, ",").get(stream -> stream.filter(StringUtil::isNotBlank).map(String::trim).toArray(n -> new String[n]));
    }

    /**
     * Gets the default roles as an array.
     *

    private static final SecureRandom RANDOM = new SecureRandom();

    private static final String BASE = StringUtil.toHex(getAddress()) + StringUtil.toHex(System.identityHashCode(RANDOM));

    /**
     * Creates a UUID.
     *
     * @return the UUID string
     */
    public static String create() {

        // search
        if (StringUtil.isNotBlank(failureUrlPager.url)) {
            cb.query().setUrl_Wildcard(failureUrlPager.url);
        }

        if (StringUtil.isNotBlank(failureUrlPager.errorCountMax)) {
            cb.query().setErrorCount_LessEqual(Integer.parseInt(failureUrlPager.errorCountMax));
        }
        if (StringUtil.isNotBlank(failureUrlPager.errorCountMin)) {

        final String password = fessConfig.getFesenPassword();
        if (StringUtil.isNotBlank(username) && StringUtil.isNotBlank(password)) {
            builder.put(Constants.FESEN_USERNAME, username);
            builder.put(Constants.FESEN_PASSWORD, password);
        }
        final String authorities = fessConfig.getFesenHttpSslCertificateAuthorities();
        if (StringUtil.isNotBlank(authorities)) {

import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.codelibs.core.lang.StringUtil;
import org.codelibs.fess.crawler.container.CrawlerContainer;
import org.codelibs.fess.crawler.exception.CrawlerSystemException;

import jakarta.annotation.PostConstruct;
import jakarta.annotation.Resource;

/**

     */
    public String normalize(final String enc) {
        if (StringUtil.isBlank(enc)) {
            return defaultEncoding;
        }

        final String newEnc = encodingMap.get(toLowerCase(enc));
        if (StringUtil.isBlank(newEnc)) {
            return enc;
        }
        return newEnc;
    }

    /**

     * @return the virtual host key, or empty string if blank or null
     */
    protected String getHostKey(final RelatedQuery entity) {
        final String key = entity.getVirtualHost();
        return StringUtil.isBlank(key) ? StringUtil.EMPTY : key;
    }

    /**
     * Retrieves related queries for a given search term.
     * The search is performed using the current virtual host context and