Prerequisite : BigInteger Basics
The probablePrime() method will return a Biginteger of bitLength bits which is prime. bitLength is provided as parameter to method probablePrime() and method will return a prime BigInteger of bitLength bits. The probability that a BigInteger returned by this method is composite and does not exceed 2^-100.
Syntax:
public static BigInteger probablePrime(int bitLength, Random rnd)
Parameters: This method accepts two parameters as shown in the above syntax and described below.
- bitLength – bitLength of the returned BigInteger.
- rnd – source of random bits used to select candidates to be tested for primality.
Return Value: This method returns a BigInteger of bitLength bits that is probably prime.
Exception:
- ArithmeticException – if bitLength < 2.
Below program illustrate the probablePrime() method:
import java.math.*;import java.util.Random;import java.util.Scanner;  public class GFG {      public static void main(String[] args)    {          Scanner sc = new Scanner(System.in);          // create a BigInteger object        BigInteger biginteger;          // create a integer value for bitLength        int length = 4;          // create a random object        Random random = new Random();          // call probablePrime method to find next probable prime        // whose bit length is equal to bitLength provided as parameter.        biginteger = BigInteger.probablePrime(length, random);          String result = "ProbablePrime whose bit length is "                        + length + " = " + biginteger;          // print result value        System.out.println(result);    }} |
Output:
ProbablePrime whose bit length is 4 = 13
