Java的大数据BigInteger的测试类

import java.math.BigInteger;
public class TestBigInteger {

	public static void main(String[] args) {
		Long before  = System.currentTimeMillis();
		System.out.println(factorial(999).toString(10));
		System.out.println("Execute Time:" + (System.currentTimeMillis()-before) + "ms");
	}
	
	public static BigInteger factorial(int max){
		BigInteger bi = BigInteger.valueOf(1);
		for (int i = 1; i <= max; i++) {
			bi = bi.multiply(BigInteger.valueOf(i));
		}
		return bi;
	}

}