public static String asAlphaNumeric(int i) {
        StringBuilder stringBuilder = new StringBuilder();
        int index = i % MAX;
        int ratio = i / MAX;

        if (index == 0) {
            ratio--;
            index = MAX;
        }

        for (int j = 0; j <= ratio; j++) {
            stringBuilder.append(ALPHABET[index - 1]);
        }
        return stringBuilder.toString();
    }
Utility class to allow for conversion from an integer to Roman numerals
or alpha-numeric symbols in line with Pages auto numbering formats.
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-apple-module/src/main/java/org/apache/tika/parser/iwork/AutoPageNumberUtils.java