class XssValidator implements ConstraintValidator<Xss, String>
{
    private static final String HTML_PATTERN = "<(\\S*?)[^>]*>.*?|<.*? />";

    @Override
    public boolean isValid(String value, ConstraintValidatorContext constraintValidatorContext)
    {
        if (StringUtils.isBlank(value))
        {
            return true;
        }
        return !containsHtml(value);
    }

    public static boolean containsHtml(String value)
    {<FILL_FUNCTION_BODY>}
}

        StringBuilder sHtml = new StringBuilder();
        Pattern pattern = Pattern.compile(HTML_PATTERN);
        Matcher matcher = pattern.matcher(value);
        while (matcher.find())
        {
            sHtml.append(matcher.group());
        }
        return pattern.matcher(sHtml).matches();
    
<no_super_class>