获取当前天数是这年的第几天

public class TestYear {

 public static void main(String args[]) {
  int day, month, year, sum, leap;
  sum = 1000;
  String str;
  str = "2010";
  year = Integer.parseInt(str);
  str = "2";
  month = Integer.parseInt(str);
  str = "4";
  day = Integer.parseInt(str);
  System.out.println(year + " " + month + " " + day);

  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;// eg:假如为3月5日 那么sum表示第“sum=59+5”天
  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，总天数自加一天
   sum++;
  if (sum > 365)
   System.out.println("data error");
  else
   System.out.println("It is the" + " " + sum + "th" + " " + "day");
 }
}