java中求兩個日期間隔天數

之前在看到很多類似這樣的寫法

(date1.getTime()-date2.getTime())/24*60*60*1000 

這樣得到的天數並不是很準確，比如昨天的10點，到今天某個時間計算出來可能並不是間隔一天，而實際上間隔天數並不需要具體的時間，因此需要把時間清零來計算。

public static Long getDaysBetween(Date startDate, Date endDate) {
		Calendar fromCalendar = Calendar.getInstance();
		fromCalendar.setTime(startDate);
		fromCalendar.set(Calendar.HOUR_OF_DAY, 0);
		fromCalendar.set(Calendar.MINUTE, 0);
		fromCalendar.set(Calendar.SECOND, 0);
		fromCalendar.set(Calendar.MILLISECOND, 0);

		Calendar toCalendar = Calendar.getInstance();
		toCalendar.setTime(endDate);
		toCalendar.set(Calendar.HOUR_OF_DAY, 0);
		toCalendar.set(Calendar.MINUTE, 0);
		toCalendar.set(Calendar.SECOND, 0);
		toCalendar.set(Calendar.MILLISECOND, 0);

		return (toCalendar.getTime().getTime() - fromCalendar.getTime().getTime()) / (1000 * 60 * 60 * 24);
	}