class StringUtils {

    public static String join(String[] strings, String separator) {
        if (strings == null || strings.length == 0) {
            return EMPTY;
        }
        StringBuilder sb = new StringBuilder();
        for (String string : strings) {
            if (isNotBlank(string)) {
                sb.append(string).append(separator);
            }
        }
        return sb.length() > 0 ? sb.substring(0, sb.length() - separator.length()) : StringUtils.EMPTY;
    }

}