100000的阶乘

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.math.BigInteger;

/*
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 * and open the template in the editor.
 */
/**
 *
 * @author corywu
 */
public class Factorial {

    public static double factorial(int num) {
        if (num == 1) {
            return 1;
        } else {
            return num * factorial(num - 1);
        }
    }

    public static void main(String args[]) {

           FileOutputStream fos = null;
        try {
            System.out.println(factorial(10));
            BigInteger x = BigInteger.valueOf(1);
            for (int i = 2; i <= 100000; i++) {
                x = x.multiply(BigInteger.valueOf(i));
            }
            fos = new FileOutputStream("c:\\abc.txt");
            OutputStreamWriter opsw = new OutputStreamWriter(fos);
            try {
                opsw.write(x.toString());
                opsw.flush();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        } catch (FileNotFoundException ex) {
            ex.printStackTrace();
        } finally {
            try {
                fos.close();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }



    }
}