Java Utililty Methods Long Number Array Convert

if (array.length == 0)
    return "[]";
StringBuilder sb = new StringBuilder(array.length << 4);
sb.append('[');
for (long o : array) {
    sb.append(Long.toString(o));
    sb.append(',');
sb.setCharAt(sb.length() - 1, ']');
return sb.toString();

byte[] r = new byte[d.length * 8];
for (int i = 0; i < d.length; i++) {
    byte[] s = longToBytes(d[i]);
    for (int j = 0; j < 8; j++)
        r[8 * i + j] = s[j];
return r;

int[] ret = new int[longs.length * 2];
for (int i = 0; i < longs.length; i++) {
    ret[i] = (int) (longs[i] >>> 32);
    ret[i + 1] = (int) longs[i];
return ret;