22 [程序 22 递归求阶乘] 题目:利用递归方法求 5!. 程序分析:递归公式:fn=fn_1*4! package cskaoyan; public class cskaoyan22 { @org.junit.Test public void recursion() { long number = 5; System.out.println(factorial(number)); } private long factorial(long number) { if (number == 1