java 获取两个日期之间的天数

public static String calcTwoDate(Date date ,Date date2){        Calendar calendar = Calendar.getInstance();        calendar.setTime(date);        Calendar calendar2 = Calendar.getInstance();        calendar2.setTime(date2);        long n  =(calendar.getTimeInMillis()-calendar2.getTimeInMillis())/(24*60*60*1000);        return String.valueOf(Math.abs(n));    }