Simple joda-time comparison demo

dates.java

int difference = 0;
DateTime start = new DateTime(source);
DateTime end = new DateTime(target);
if (source.after(target)) {
  start = end;
  end = new DateTime(source);
}
switch (type) {
  case MONTHS:
    difference = Months.monthsBetween(start, end).getMonths();
  break;
  case DAYS:
    difference = Days.daysBetween(start, end).getDays();
  break;
  case YEARS:
    difference = Years.yearsBetween(start, end).getYears();
  break;
  case HOURS:
    difference = Hours.hoursBetween(start, end).getHours();
  break;
  case MINUTES:
    difference = Minutes.minutesBetween(start, end).getMinutes();
  break;
}