java计算日期之差，java计算,做项目时，碰到计算日期的

java计算日期之差，java计算,做项目时，碰到计算日期的

做项目时，碰到计算日期的天数差，没有认真的想过，就从网上找两个大牛写的，挺好用。

[Java]代码

private int daysBetween(Date now, Date returnDate) {        Calendar cNow = Calendar.getInstance();        Calendar cReturnDate = Calendar.getInstance();        cNow.setTime(now);        cReturnDate.setTime(returnDate);        setTimeToMidnight(cNow);        setTimeToMidnight(cReturnDate);        long todayMs = cNow.getTimeInMillis();        long returnMs = cReturnDate.getTimeInMillis();        long intervalMs = todayMs - returnMs;        return millisecondsToDays(intervalMs);    }    private int millisecondsToDays(long intervalMs) {        return (int) (intervalMs / (1000 * 86400));    }    private void setTimeToMidnight(Calendar calendar) {        calendar.set(Calendar.HOUR_OF_DAY, 0);        calendar.set(Calendar.MINUTE, 0);        calendar.set(Calendar.SECOND, 0);    }