public static void main(String[] args) { // TODO Auto-generated method stub int year = 2012, lemp; int month = 2, day = 21; int i = 0; switch (month) { case 1: i = 0; break; case 2: i = 31; break; case 3: i = 59; break; case 4: i = 90; break; case 5: i = 120; break; case 6: i = 151; break; case 7: i = 181; break; case 8: i = 212; break; case 9: i = 243; break; case 10: i = 273; break; case 11: i = 304; break; case 12: i = 334; break; // default; } i = i + day; if (year % 400 == 0 || (year % 100 != 0 && year % 4 == 0)) { // 判断是否为闰年 lemp = 1; } else lemp = 0; if (lemp == 1 && month > 2) { // 如果是闰年且月份大于二，总天数应该加一 i++; } System.out.println("这一天是以年中的第：" + i + "天！"); }注意一月是31天哦！！！按照你的思路可以这样改，但是还有别的更好办法
