Java Utililty Methods BigInteger to

byte[] bytes = bigInteger.toByteArray();
if (bytes[0] == 0) {
    return Arrays.copyOfRange(bytes, 1, bytes.length);
return bytes;

String s = n.toString();
int size = s.length();
int[] retval = new int[size];
for (int i = 0; i < size; i++) {
    retval[i] = Integer.parseInt(String.valueOf(s.charAt(i)));
return retval;

byte[] result = new byte[8];
byte[] tmp = value.toByteArray();
if (tmp.length > 8) {
    System.arraycopy(tmp, tmp.length - 8, result, 0, 8);
} else {
    System.arraycopy(tmp, 0, result, 8 - tmp.length, tmp.length);
return result;
...

return bytesToHex(bigIntegerToBytes(bigInteger));

if (number == null) {
    return new ArrayList<>(0);
String bitArray = number.toString(2);
List<Integer> result = new ArrayList<>();
int length = bitArray.length();
for (int index = length - 1; index >= 0; --index) {
    if (bitArray.charAt(index) == '1') {
...

if (value == null) {
    return "null";
} else if (value.signum() < 0) {
    return "-0x" + value.negate().toString(16);
} else {
    return "0x" + value.toString(16);

byte[] buf = new byte[len];
if (a.bitLength() > len * 8)
    throw new NumberFormatException("BigInteger doesn't fit into array");
byte[] b = a.toByteArray();
if (b.length == len + 1)
    if (b[0] == 0)
        for (int i = 0; i < buf.length; i++)
            buf[i] = b[i + 1];
...

List<Integer> dataList = new ArrayList<Integer>();
for (int i = 0; data.bitCount() > 0; i++, data = data.shiftRight(1)) {
    if (data.testBit(0))
        dataList.add(i);
int[] dataArr = new int[dataList.size()];
for (int i = 0; i < dataArr.length; i++)
    dataArr[i] = dataList.get(i);
...

String hashKey = keyValue.toString(16);
if (hashKey.length() > 32) {
    throw new Exception("Invalid value.");
StringBuilder sb = new StringBuilder();
for (int i = 0; i < 32 - hashKey.length(); ++i) {
    sb.append("0");
sb.append(hashKey);
return sb.toString().toUpperCase();

return big.toString(16);