用递归计算阶乘！

需求：递归计算阶乘！

package suanfa;

import java.util.Scanner;
public class Jiecheng {
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
		System.out.println("请输入一个整数：");
		long n = scan.nextLong();
		System.out.println(n+"!="+jiecheng(n));
		
	}

	//调用阶乘方法
	public static long jiecheng(long n){
		long i;
		if (n<0)
			return 0;    //小于0 返回0
		if (n == 1)
			return 1;    //等于1 返回1
		else
			return n*jiecheng(n-1);
	}
}