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

class TimeCalculator { String updateTime;

     public TimeCalculator(String time)
      {
        // time should be in 24 hours format like 15/06/2016 17:39:20  
        this.updateTime = time;
      }

     public String getTimeDifference()
     {
        String td=null;
       // get Current Time
        SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy hh:mm:ss");
        Date currentDate = new Date();
        Calendar calendar = new GregorianCalendar();
        calendar.setTime(currentDate);

        int c_year = calendar.get(Calendar.YEAR);
        int c_month = calendar.get(Calendar.MONTH) + 1;
        int c_day = calendar.get(Calendar.DAY_OF_MONTH);

        // get Editing Time

        Date edit_date = sdf.parse(updateTime);
        Calendar edit_calendar = new GregorianCalendar();
        edit_calendar.setTime(edit_date);

        int e_year = edit_calendar.get(Calendar.YEAR);
        int e_month = edit_calendar.get(Calendar.MONTH) + 1;
        int e_day = edit_calendar.get(Calendar.DAY_OF_MONTH);


        if(e_year==c_year&&e_month==c_month&&e_day==c_day)
            {

             int c_hours = calendar.get(Calendar.HOUR_OF_DAY);
             int c_minutes = calendar.get(Calendar.MINUTE);
             int c_seconds = calendar.get(Calendar.SECOND);

             int e_hours = edit_calendar.get(Calendar.HOUR_OF_DAY);
             int e_minutes = edit_calendar.get(Calendar.MINUTE);
             int e_seconds = edit_calendar.get(Calendar.SECOND);

      if(c_hours==e_hours&&c_minutes==e_minutes&&c_seconds==e_seconds)
         {
           td = "just now";
           return td;
          }
      else if(c_hours==e_hours&&c_minutes==e_minutes)
       {
         int d_seconds = c_seconds-e_seconds;
         td = String.valueOf(d_seconds);
         td = td+" seconds ago";
         return td;
       }
      else if(c_hours==e_hours&&c_minutes!=e_minutes)
       {
         int d_minutes = c_minutes-e_minutes;
         int d_seconds;
         if(c_seconds>e_seconds)
           {
             d_seconds = c_seconds-e_seconds;
           }else{
             d_seconds = e_seconds-c_seconds;
       }
          td = "00:"+String.valueOf(d_minutes)+":"+String.valueOf(d_seconds)+" ago";
        return td;
  }
    else
       {
        int d_minutes,d_seconds,d_hours;
        d_hours=c_hours-e_hours;
        if(c_minutes>e_minutes)
       {
         d_minutes = c_minutes-e_minutes;
       }else{
         d_minutes = e_minutes-c_minutes;
       }
        if(c_seconds>e_seconds)
          {
            d_seconds = c_seconds-e_seconds;
          }else{
            d_seconds = e_seconds-c_seconds;
          }

      td = String.valueOf(d_hours)+":"+String.valueOf(d_minutes)+":"+String.valueOf(d_seconds)+" ago";
     return td;
  }
}
 else if(e_year==c_year&&e_month==c_month&&c_day==e_day+1){
   td = "yesterday";
   return td;
 }
 else{
    td = updateTime;
    return td;
     }
}}