/* Returns the addition of two durations.
*/
public static SchemaDuration durationAdd(SchemaDuration duration1, SchemaDuration duration2) {
SchemaDuration dur = new SchemaDuration();
dur.setNegative(false); // sets isempty to false
int ym = duration1.getYearMonthValue() + duration2.getYearMonthValue();
long dt = duration1.getDayTimeValue() + duration2.getDayTimeValue();
if ((ym < 0 && dt > 0) || (ym > 0 && dt < 0))
throw new NotANumberException(
"Invalid duration result, yearmonth part differs in sign from daytime part.");
if (ym != 0) dur.setYearMonthValue(ym);
if (dt != 0) dur.setDayTimeValue(dt);
return dur;
}
/* Performs a addition of dates, times and durations.
*/
public static SchemaDateTime datetimeAdd(SchemaDateTime datetime, SchemaDuration duration) {
int months = duration.getYearMonthValue();
SchemaDateTime result = new SchemaDateTime(datetime);
result.setMonth(datetime.getMonth() + months);
int yearsOverflow;
if (result.getMonth() >= 1) yearsOverflow = (result.getMonth() - 1) / 12;
else yearsOverflow = (result.getMonth() - 12) / 12;
result.setMonth(result.getMonth() - yearsOverflow * 12);
if (yearsOverflow > 0 && result.getYear() < 0 && yearsOverflow >= -result.getYear())
result.setYear(result.getYear() + yearsOverflow + 1);
else if (yearsOverflow < 0 && result.getYear() > 0 && -yearsOverflow >= result.getYear())
result.setYear(result.getYear() + yearsOverflow - 1);
else result.setYear(result.getYear() + yearsOverflow);
boolean leapYear =
(result.getYear() % 4 == 0)
&& ((result.getYear() % 100 != 0) || (result.getYear() % 400 == 0));
int daysInMonth =
result.getMonth() == 2
? leapYear ? 29 : 28
: (30 + ((result.getMonth() & 1) ^ ((result.getMonth() >> 3) & 1)));
if (result.getDay() > daysInMonth) result.setDay(daysInMonth);
long tv =
result.getTimeValue() + duration.getDayTimeValue() + result.getTimezoneOffset() * 60000;
result.setTimeFromTimeValue(tv);
result.setDateFromTimeValue(tv);
return result;
}
