java中求两个日期间隔天数

java中求两个日期间隔天数

之前在看到很多类似这样的写法 

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

这样得到的天数并不是很准确，比如昨天的10点，到今天某个时间计算出来可能并不是间隔一天，而实际上间隔天数并不需要具体的时间，因此需要把时间清零来计算。 

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);
    }