Java中输入年月日计算第一天是倒数第几天

Question

Java中输入年月日计算第一天是倒数第几天

Answer 1

用Calendar类,里面有一个算某一天是一年的第几天的,然后你用那一年的总天数减一下就能得到是倒数第几天了.
自己输入传入time 的值
Calendar cal = Calendar.getInstance();
//通过输入传入年月日
cal.set(int year, int month, int date);
if(cal.get(Calendar.YEAR)%100 == 0) {
if(cal.get(Calendar.YEAR)%400 == 0) {
System.out.println("倒数第"+(366-cal.get(Calendar.DAY_OF_YEAR))+"天");
}
}else {
if(cal.get(Calendar.YEAR)%4 == 0) {
System.out.println("倒数第"+(366-cal.get(Calendar.DAY_OF_YEAR))+"天");
}else {
System.out.println("倒数第"+(365-cal.get(Calendar.DAY_OF_YEAR))+"天");
}
}