Java - fun converting a string (4 chars) to int and back

freedev :

Please don't ask why but I have to store a string (max 4 char) in an integer value (so 4 bytes).

First I wrote this and it works:

String value = "AAA";
int sum = IntStream.range(0, value.length())
                   .limit(4)
                   .map(i -> value.charAt(i) << (i * 8))
                   .sum();

System.out.println(sum);

I was unable to think a functional solution for the way back.

StringBuffer out = new StringBuffer();
while (sum > 0) {
    int ch = sum & 0xff;
    sum >>= 8;
    out.append((char) ch);
}

Any idea to write the way back (to "AAA") in a functional way?

Michel_T. :

That's pretty similar to yours, but maybe will be helpful

    String str = IntStream.iterate(sum, s -> s > 0, s -> s >> 8)
            .mapToObj(s -> String.valueOf((char)(s & 0xff)))
            .collect(Collectors.joining());