java的大数类

package test;
import java.math.*;
public class LargeFactorial {
    public static BigInteger factorial(long n){          
        BigInteger result = BigInteger.ONE;
        for(long i = 1; i <= n; i++){
            result = result.multiply(new BigInteger(i+"")); 
        } //注意上面因为要把数字i转化为字符，所以说要加上一个空字符
        return result;
    }
    public static void main(String[] args){
        System.out.println("50! is \n" + factorial(50));
    }
}