Java Utililty Methods BigInteger Calculate

List of utility methods to do BigInteger Calculate

  1. HOME
  2. Java
  3. B
  4. BigInteger Calculate

Description

The list of methods to do BigInteger Calculate are organized into topic(s).

Method

byterightshift(byte b1, BigInteger b2)
rightshift 
return (byte) ((b1 & 0xFF) >>> b2.intValue());
booleansaveKey(File destDir, String fileName, BigInteger modulus, BigInteger publicExponent)
save Key 
try {
    FileOutputStream fos = new FileOutputStream(destDir + File.separator + fileName);
    ObjectOutputStream oos = new ObjectOutputStream(new BufferedOutputStream(fos));
    oos.writeObject(modulus);
    oos.writeObject(publicExponent);
    oos.close();
    fos.close();
    return true;
...
voidsaveToFile(String fileName, BigInteger mod, BigInteger exp)
Save modulus and exponent of a key to file 
ObjectOutputStream oout = null;
try {
    oout = new ObjectOutputStream(new BufferedOutputStream(new FileOutputStream(fileName)));
    oout.writeObject(mod);
    oout.writeObject(exp);
} catch (IOException e) {
    e.printStackTrace();
} finally {
...
StringserializeModexpNoBase(BigInteger[] modexp, boolean withResult)
Helper method creating the JSON string for a single modexp without base and with or without given result. 
return withResult
        ? String.format("{\"m\":\"%s\",\"e\":\"%s\",\"r\":\"%s\"}", modexp[0].toString(16),
                modexp[2].toString(16), modexp[3].toString(16))
        : String.format("{\"m\":\"%s\",\"e\":\"%s\"}", modexp[0].toString(16), modexp[2].toString(16));
StringserializeModexpResponse(BigInteger response)
serialize Modexp Response 
return String.format("{\"r\":\"%s\"}", response.toString(16));
StringserializeQuery(BigInteger modulus, BigInteger base, BigInteger exponent, boolean brief, String... modexps)
Helper method creating the JSON string for a modexp-queryResponse with optional default base, exponent and modulus. 
String query = "{";
query = modulus != null ? query + "\"m\":\"" + modulus.toString(16) + "\"," : query;
query = base != null ? query + "\"b\":\"" + base.toString(16) + "\"," : query;
query = exponent != null ? query + "\"e\":\"" + exponent.toString(16) + "\"," : query;
query = brief ? query : query + "\"brief\":false,";
query = modexps.length > 0 ? query + "\"modexps\":[" : query;
for (int i = 0; i < modexps.length; i++) {
    query += modexps[i];
...
BigIntegershift(BigInteger integer, int distance)
Returns a BigInteger whose value is shifted by the given distance. 
if (integer == null)
    return null;
return integer.shiftLeft(distance);
BigIntegershiftLeft(final BigInteger register, final BigInteger input, final int n)
Shifts register left by n bits and sets these n bits to the n rightmost bits of input. 
final BigInteger cutSuffix = getNRightmostBits(input, n);
return register.shiftLeft(n).or(cutSuffix);
BigInteger[]split(BigInteger maxValue, int numberOfSplits)
Splits the given BigInteger into numberOfSplits parts 
BigInteger[] splits = new BigInteger[numberOfSplits - 1];
BigInteger sizeOfEachSplit = maxValue.divide(BigInteger.valueOf(numberOfSplits));
for (int i = 1; i < numberOfSplits; i++) {
    splits[i - 1] = sizeOfEachSplit.multiply(BigInteger.valueOf(i));
return splits;
BigInteger[]splitBigInt(BigInteger value, int n)
split Big Int 
if (n <= 1) {
    return new BigInteger[] { value };
BigInteger[] values = new BigInteger[n];
BigInteger total = BigInteger.ZERO;
for (int i = 0; i < n; ++i) {
    values[i] = value.multiply(BigInteger.valueOf(Math.round(Math.random() * 100)));
    total = total.add(values[i]);
...