Numbers of hours in two different dates

Question

I have two days and it is in df = new SimpleDateFormat("yyyyMMddHHmmss") format.
start date is 20041203180000 ( year, month, day of month, hours, minutes )
end date is 20041204050000
How do I calculate the number of hours between those two days.
Thanks

Answer 1

I think this would work (I was bored)...
public static int getCountBetween(Date d1, Date d2, int field) {
   if(d1 == null || d2 == null) {
      throw new NullPointerException();
   if(d1 == d2 || d1.equals(d2)) {
      return 0;
   if(d1.after(d2)) {
      Date dx = d1;
      d1 = d2;
      d2 = dx;
   Calendar c1 = new GregorianCalendar();
   c1.setTime(d1);
   Calendar c2 = new GregorianCalendar();
   c2.setTime(d2);
   int count = 0;
   while(c1.before(c2)) {
      c1.roll(field, 1);
      count++;
   return count;
}That's pretty generic,... field would be Calendar.MONTH or Calendar.HOUR_OF_DAY or whatever field. It's probably not as quick as other ways...