java 输入某年某月某日，判断这一天是这一年的第几天

import java.util.*;public class test {  public static void main (String[]args){    int day=0;    int month=0;    int year=0;    int sum=0;    int leap;     System.out.print("请输入年,月,日/n");     Scanner input = new Scanner(System.in);    year=input.nextInt();    month=input.nextInt();    day=input.nextInt();    switch(month) /*先计算某月以前月份的总天数*/     {     case 1:      sum=0;break;     case 2:      sum=31;break;     case 3:      sum=59;break;     case 4:      sum=90;break;     case 5:      sum=120;break;     case 6:      sum=151;break;     case 7:      sum=181;break;     case 8:      sum=212;break;     case 9:      sum=243;break;     case 10:      sum=273;break;     case 11:      sum=304;break;     case 12:      sum=334;break;     default:      System.out.println("data error");break;    }     sum=sum+day; /*再加上某天的天数*/     if(year%400==0||(year%4==0&&year%100!=0))/*判断是不是闰年*/       leap=1;     else       leap=0;     if(leap==1 && month>2)/*如果是闰年且月份大于2,总天数应该加一天*/       sum++;     System.out.println("It is the the day:"+sum);    }}