public boolean impossible(byte[] myBytes) {
  if (myBytes.length == 0)
    return false;
  String string = new String(myBytes, "UTF-8");
  return string.length() == 0;
}

public static void main(String[] args) throws UnsupportedEncodingException {
    byte[] test = new byte[3];
    byte[] end = new byte[test.length];

    if (impossible(test)) {
        System.out.println(Arrays.toString(test));
    }
    do {
        increment(test, 0);
        if (impossible(test)) {
            System.out.println(Arrays.toString(test));
        }
    } while (!Arrays.equals(test, end));

}

private static void increment(byte[] arr, int i) {
    arr[i]++;
    if (arr[i] == 0 && i + 1 < arr.length) {
        increment(arr, i + 1);
    }
}

public static boolean impossible(byte[] myBytes) throws UnsupportedEncodingException {
    if (myBytes.length == 0) {
        return false;
    }
    String string = new String(myBytes, "UTF-8");
    return string.length() == 0;
}