How to find the number of days between two dates in java or groovy?

Question

I have a method which uses following logic to calculate difference between days.

long diff = milliseconds2 - milliseconds1;
long diffDays = diff / (24 * 60 *         


        

Answer 1

Find out the number of days in between two given dates:

@Test

public class Demo3 {

    public static void main(String[] args) {
        String dateStr ="2008-1-1 1:21:28";
        String dateStr2 = "2010-1-2 1:21:28";
        SimpleDateFormat format = new SimpleDateFormat("yyy-MM-dd HH:mm:ss");
        SimpleDateFormat format2 = new SimpleDateFormat("yyy-MM-dd HH:mm:ss");
        try {
            Date date2 = format.parse(dateStr2);
            Date date = format.parse(dateStr);

            System.out.println("distance is :"+differentDaysByMillisecond(date,date2));
        }catch(ParseException e ){
            e.printStackTrace();
        }
    }

//get Days method

    private static int differentDaysByMillisecond(Date date, Date date2) {
        return (int)((date2.getTime()-date.getTime())/1000/60/60/24);
    }

}