Java,Calendar 获得明天凌晨的时间time

/**
* 获得明天凌晨的时间time
*
* @return
*/
private long getNextDayZeroTime()
{
Calendar calendar = Calendar.getInstance();
calendar.add(Calendar.DAY_OF_MONTH, 1);
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0); return calendar.getTimeInMillis();
}/**
* 根据给定的time获得昨天凌晨的时间
* 1、time=null,默认系统时间的昨天凌晨时间
* 2、time!=null,获得给定time的所在天的前一天的凌晨时间
*
* @return 昨天凌晨的时间
*/
private static long getYesterdayZeroTimeByTime(Long time) {
Calendar calendar = Calendar.getInstance();
if (time != null) {
calendar.setTimeInMillis(time);
}
calendar.add(Calendar.DAY_OF_MONTH, -1);
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0); return calendar.getTimeInMillis();
}