How to calculate time difference in java?

Question

I want to subtract two timeperiods say 16:00:00 from 19:00:00. Is there any java function for this? The results can be in milliseconds, seconds, or minutes.

Answer 1

Аlternative option if time from different days is taken, for example: 22:00 and 01:55.

public static long getDiffTime(Date date1, Date date2){
        if (date2.getTime() - date1.getTime() < 0) {// if for example date1 = 22:00, date2 = 01:55.
            Calendar c = Calendar.getInstance();
            c.setTime(date2);
            c.add(Calendar.DATE, 1);
            date2 = c.getTime();
        } //else for example date1 = 01:55, date2 = 03:55.
        long ms = date2.getTime() - date1.getTime();

        //235 minutes ~ 4 hours for (22:00 -- 01:55).
        //120 minutes ~ 2 hours for (01:55 -- 03:55).
        return TimeUnit.MINUTES.convert(ms, TimeUnit.MILLISECONDS);
    }