(Factorial) Using the BigInteger class introduced in Section 10.9, you can find the factorial for a large number (e.g., 100!). Implement the factorial method using recursion

/*********************************************************************************
* (Factorial) Using the BigInteger class introduced in Section 10.9, you can     *
* find the factorial for a large number (e.g., 100!). Implement the factorial    *
* method using recursion. Write a program that prompts the user to enter an      *
* integer and displays its factorial.                                            *
*********************************************************************************/
import java.util.Scanner;
import java.math.*;

public class Exercise_18_01 {
	/** Main method */
	public static void main(String[] args) {
		// Create a Scanner
		Scanner input = new Scanner(System.in);
		System.out.print("Enter an integer: ");
		String n = input.nextLine();

		// Display factorial
		System.out.println("Factorial of " + n + " is " 
			+ factorial(new BigInteger(n)));
	}

	/** Retrun the factorial for the specified number */
	public static BigInteger factorial(BigInteger n) {
		if (n.equals(BigInteger.ZERO)) // Base case
			return BigInteger.ONE; 
		else // Recursive call
			return n.multiply(factorial(n.subtract(BigInteger.ONE)));
	}
}