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));
}