public static List<String> extractLinks(String content) {
        if (content == null || content.isEmpty()) {
            return Collections.emptyList();
        }

        List<String> extractions = new ArrayList<>();
        final Matcher matcher = LINKS_PATTERN.matcher(content);
        while (matcher.find()) {
            extractions.add(matcher.group());
        }
        return extractions;

    }
Extract urls from plain text.

@param content The plain text content to examine
@return List of urls within found in the plain text
tika-core/src/main/java/org/apache/tika/utils/RegexUtils.java