java计算两个日期之间相差的天数

public static int daysBetween(Date smdate, Date bdate) throws ParseException { SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); smdate = sdf.parse(sdf.format(smdate)); bdate = sdf.parse(sdf.format(bdate)); Calendar cal = Calendar.getInstance(); cal.setTime(smdate); long time1 = cal.getTimeInMillis(); cal.setTime(bdate); long time2 = cal.getTimeInMillis(); long between_days = (time2 - time1) / (1000 * 3600 * 24); return Integer.parseInt(String.valueOf(between_days)); }