}

  static CommonPattern compilePattern(String pattern) {
    Preconditions.checkNotNull(pattern);
    return patternCompiler.compile(pattern);
  }

  static boolean patternCompilerIsPcreLike() {
    return patternCompiler.isPcreLike();
  }

  private static PatternCompiler loadPatternCompiler() {
    // We want the JDK Pattern compiler:
    // - under Android (where it hurts startup performance)

            return false;
        }

        Pattern pattern = (Pattern) propMap.get(USER_CODE_PATTERN);
        if (pattern == null) {
            pattern = Pattern.compile(getUserCodePattern());
            propMap.put(USER_CODE_PATTERN, pattern);
        }
        return pattern.matcher(userCode).matches();
    }

    String getQueryCollapseInnerHitsSorts();

                final Pattern pattern = Pattern.compile(value);
                paramMap.put(URL_EXCLUDE_PATTERN, pattern);
                if (logger.isDebugEnabled()) {
                    logger.debug("Using exclude pattern: {}", pattern);
                }
            }
            if (paramMap.get(URL_EXCLUDE_PATTERN) instanceof final Pattern pattern) {
                if (pattern.matcher(url).matches()) {

    /** Format identifier for PDF date parsing */
    private static final String PDF_DATE = "pdf_date";

    /** Regular expression pattern for matching email addresses */
    private static final Pattern EMAIL_ADDRESS_PATTERN =
            Pattern.compile("[A-Z0-9._%+-]+@[A-Z0-9.-]+\\.[A-Z]{2,6}", Pattern.CASE_INSENSITIVE);

    /**
     * Cache for storing resource file modification timestamps to enable cache busting.

    }

    /**
     * Converts a GSA URL pattern into a regular expression pattern suitable for Fess.
     * Handles various GSA pattern formats including regexp, contains, and URL-based patterns.
     *
     * @param s the input GSA pattern string
     * @return a regular expression pattern string, or empty string for comments/invalid patterns
     */
    protected String getFilterPath(final String s) {

        // Pattern uses Object (identity) equality, so we have to reach
        // inside to compare individual fields.
        return Objects.equals(pattern.pattern(), that.pattern.pattern())
            && pattern.flags() == that.pattern.flags();
      }
      return false;
    }

    @Override
    public String toString() {
      String patternString =

     *
     * @param cmdList the command list to add properties to
     * @param regex the regular expression pattern to match property names
     */
    protected void addFessCustomSystemProperties(final List<String> cmdList, final String regex) {
        if (StringUtil.isNotBlank(regex)) {
            final Pattern pattern = Pattern.compile(regex);

   *     example, {@code "rpc-pool-%d"} will generate thread names like {@code "rpc-pool-0"}, {@code
   *     "rpc-pool-1"}, {@code "rpc-pool-2"}, etc.
   * @return this for the builder pattern
   */
  @CanIgnoreReturnValue
  public ThreadFactoryBuilder setNameFormat(String nameFormat) {
    String unused = format(nameFormat, 0); // fail fast if the format is bad or null
    this.nameFormat = nameFormat;

        .containsExactly("Testing", "rocks", "Debugging", "sucks")
        .inOrder();
  }

  @GwtIncompatible // java.util.regex.Pattern
  private static Pattern literalDotPattern() {
    return Pattern.compile("\\.");
  }

  @GwtIncompatible // java.util.regex.Pattern
  public void testPatternSplitWithDoubleDelimiterOmitEmptyStrings() {
    String doubled = "a..b.c";

    /**
     * Cache for client rules mapping client names to their corresponding URL patterns.
     * This cache improves performance by avoiding repeated parsing of client configuration rules.
     * The key is the rule string, and the value is a pair containing the client name and compiled pattern.
     */
    protected ConcurrentHashMap<String, Pair<String, Pattern>> clientRuleCache = new ConcurrentHashMap<>();

    /**