Java求n的阶乘

import java.util.Scanner;
//递归求n的阶乘
public class demo2 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.println("输入所求阶乘n:");
        int n = input.nextInt();
        demo2 demo = new demo2();
        demo.fun(n);
        System.out.println(n+"的阶乘为："+demo.fun(n));
    }
    public int fun(int n){
        if(n==1){
            return 1;
        }else {
            return n*fun(n-1);
        }
    }
}