方法一：通过Calendar类得日期比较，在这需要考虑闰年和平年，也要考虑跨年份
/**
* date2比date1多的天数
* @param date1
* @param date2
* @return
*/
public static int differentDays(Date date1,Date date2)
{
Calendar cal1 = Calendar.getInstance();
cal1.setTime(date1); Calendar cal2 = Calendar.getInstance();
cal2.setTime(date2);
int day1= cal1.get(Calendar.DAY_OF_YEAR);
int day2 = cal2.get(Calendar.DAY_OF_YEAR); int year1 = cal1.get(Calendar.YEAR);
int year2 = cal2.get(Calendar.YEAR);
if(year1 != year2) //不同一年
{
int timeDistance = 0 ;
for(int i = year1 ; i < year2 ; i ++)
{
if(i%4==0 && i%100!=0 || i%400==0) //闰年
{
timeDistance += 366;
}
else //不是闰年
{
timeDistance += 365;
}
} return timeDistance + (day2-day1) ;
}
else //同一年
{
System.out.println("判断day2 - day1 : " + (day2-day1));
return day2-day1;
}
}
方法二：转化为毫秒数，再除以一天得毫秒数
/**
* 通过时间秒毫秒数判断两个时间的间隔
* @param date1
* @param date2
* @return
*/
public static int differentDaysByMillisecond(Date date1,Date date2)
{
int days = (int) ((date2.getTime() - date1.getTime()) / (1000*3600*24));
return days;
}