Java Utililty Methods BigInteger From

BigInteger byteArrayToBigInteger(final byte[] data)
Convert a BCD byte[] to BigInteger

StringBuilder stringBuilder = new StringBuilder(data.length * 2);
for (final byte aData : data) {
 int digit = (aData & 0xF0) >> 4;
 if (digit < 0 || digit > 9) {
 throw new IllegalArgumentException("Invalid digit: " + digit);
 stringBuilder.append((char) (digit + 0x30));
 digit = aData & 0x0F;
...

BigInteger ByteArrayToBigIntegerWithoutSign(byte[] array)
Convert an array of bytes to a non-negative big integer.

return new BigInteger(1, array);

BigInteger bytesToBigInteger(byte[] buffer)
This function converts the bytes in a byte array to its corresponding big integer value.

return new BigInteger(buffer);

BigInteger bytesToBigInteger(byte[] data)
bytes To Big Integer

return new BigInteger(1, data);

BigInteger bytesToBigInteger(byte[] data, int[] offset)
Return the BigInteger represented by the bytes in data staring at offset offset[0].

int length = bytesToInt(data, offset);
byte[] bytes = new byte[length];
offset[0] += memcpy(bytes, 0, data, offset[0], length);
return new BigInteger(bytes);

BigInteger convertToBigInteger(String s)
convert To Big Integer

if ((s == null) || s.equals("")) {
 return null;
if (s.startsWith("+")) {
 s = s.substring(1);
return convertToInteger(s);

BigInteger convertToBigInteger(String sequence)
convert To Big Integer

BigInteger biSequence = BigInteger.ZERO;
int kmerSize = sequence.length();
for (int i = 0; i < kmerSize; i++) {
 char ch = sequence.charAt(i);
 if (ch == 'A') {
 biSequence = biSequence.add(BigInteger.valueOf(0));
 } else if (ch == 'C') {
 biSequence = biSequence.add(BigInteger.valueOf(1));
...

BigInteger getUnsignedBigInteger(byte[] data, int offset, int length)
Returns a positive BigInteger from the given bytes.

if (length == 0) {
 return BigInteger.ZERO;
byte[] value = new byte[length + 1];
System.arraycopy(data, offset, value, 1, length);
return new BigInteger(value);

BigInteger getUnsignedBigInteger(long x)
Ensure that the passed long parameter will be interpreted as a positive value.

BigInteger z = BigInteger.valueOf(x);
if (z.signum() < 0)
 return z.add(x64);
else
 return z;

BigInteger string2BigInteger(String plaintext)
String 2 big integer big integer.

String msg = base64Encode(plaintext);
return toBigInteger(msg);