对BigDecimal中multiply的阶乘方法的理解

   
   

    
    

     
     package controlFlow;
    
    
    
    

     
      
    
    
    
    

     
     import java.math.BigDecimal;
    
    
    
    

     
      
    
    
    
    

     
     public class Factorial {
    
    
    
    

     
     	public static void main(String[] args) {
    
    
    
    

     
     	BigDecimal sum = new BigDecimal(0.0);
    
    
    
    

     
     	BigDecimal factorial = new BigDecimal(1.0);
    
    
    
    

     
     	int i = 1;
    
    
    
    

     
     	while (i <= 10) 
    
    
    
    

     
     	{
    
    
    
    

     
     		sum = sum.add(factorial);
    
    
    
    

     
     		++i;
    
    
    
    

     
     		factorial = factorial.multiply(new BigDecimal(1.0 / i));
    
    
    
    

     
     	}
    
    
    
    

     
     	System.out.println("1+1/2!+1/3!...1/10的计算结果等于: n" + sum);
    
    
    
    

     
     	}
    
    
    
    

     
     }