Language: Java
Label: safe
CWE: CWE-79 \u2014 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Code:
    private static Optional<String> getScheme(String uri) {
        var s = StringUtils.trimToEmpty(uri).toLowerCase(Locale.ROOT);
        return s.indexOf(':') >= 0 ? Optional.of(StringUtils.substringBefore(s, ':')) : Optional.empty();
    }