我想计算两个日期之间的差异。 目前，我正在做:
Calendar firstDate = Calendar.getInstance();
firstDate.set(Calendar.DATE, 15);
firstDate.set(Calendar.MONTH, 4);
firstDate.get(Calendar.YEAR);
int diff = (new Date().getTime - firstDate.getTime)/(1000 * 60 * 60 * 24)
这给了我输出 0。但是我希望当 new Date() 为 15 时我应该得到输出 0。目前新日期是 14。这使我的进一步计算错误，我很困惑如何解决这个问题。请提出建议。
最佳答案
Finding the difference between two dates isn't as straightforward as subtracting the two dates and dividing the result by (24 * 60 * 60 * 1000). Infact, its erroneous!
/* Using Calendar - THE CORRECT (& Faster) WAY**/
//assert: startDate must be before endDate
public static long daysBetween(final Calendar startDate, final Calendar endDate) {
int MILLIS_IN_DAY = 1000 * 60 * 60 * 24;
long endInstant = endDate.getTimeInMillis();
int presumedDays = (int) ((endInstant - startDate.getTimeInMillis()) / MILLIS_IN_DAY);
Calendar cursor = (Calendar) startDate.clone();
cursor.add(Calendar.DAY_OF_YEAR, presumedDays);
long instant = cursor.getTimeInMillis();
if (instant == endInstant)
return presumedDays;
final int step = instant < endInstant ? 1 : -1;
do {
cursor.add(Calendar.DAY_OF_MONTH, step);
presumedDays += step;
} while (cursor.getTimeInMillis() != endInstant);
return presumedDays;
}
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关于java - Java中的日期差计算，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/10588640/