/**
* Adds a Duration to this Date/Time type as defined in <a
* href="http://www.w3.org/TR/xmlschema-2/#adding-durations-to-dateTimes">Adding Duration to
* dateTimes (W3C XML Schema, part 2 appendix E).</a> This version is using the algorithm defined
* in the document from W3C, next version may optimize it.
*
* @param duration the duration to add
*/
public void addDuration(Duration duration) {
int temp = 0;
int carry = 0;
int sign = (duration.isNegative()) ? -1 : 1;
// don't use getter methods but use direct field access for dateTime
// in order to have the behaviour defined in the Recommendation document
// Months
try {
temp = _month + sign * duration.getMonth();
carry = fQuotient(temp - 1, 12);
temp = modulo(temp - 1, 12) + 1;
this.setMonth((short) temp);
} catch (OperationNotSupportedException e) {
// if there is no Month field in the date/time datatypes
// we do nothing else we throw a runTime exception
if (!((this instanceof Time) || (this instanceof GYear) || (this instanceof GDay))) throw e;
}
// Years
try {
temp = _century * 100 + _year + sign * duration.getYear() + carry;
short century = (short) (temp / 100);
temp = temp % 100;
this.setCentury(century);
this.setYear((short) temp);
} catch (OperationNotSupportedException e) {
// if there is no Year field in the date/time datatypes
// we do nothing else we throw a runTime exception
if (!((this instanceof Time) || (this instanceof GMonthDay))) throw e;
}
// Seconds
try {
temp = _second + sign * duration.getSeconds();
carry = fQuotient(temp, 60);
temp = modulo(temp, 60);
this.setSecond((short) temp, this.getMilli());
} catch (OperationNotSupportedException e) {
// if there is no Second field in the date/time datatypes
// we do nothing else we throw a runTime exception
if (this instanceof Time) throw e;
}
// Minutes
try {
temp = _minute + sign * duration.getMinute() + carry;
carry = fQuotient(temp, 60);
temp = modulo(temp, 60);
this.setMinute((short) temp);
} catch (OperationNotSupportedException e) {
// if there is no Minute field in the date/time datatypes
// we do nothing else we throw a runTime exception
if (this instanceof Time) throw e;
}
// Hours
try {
temp = _hour + sign * duration.getHour() + carry;
carry = fQuotient(temp, 24);
temp = modulo(temp, 24);
this.setHour((short) temp);
} catch (OperationNotSupportedException e) {
// if there is no Hour field in the date/time datatypes
// we do nothing else we throw a runTime exception
if (this instanceof Time) throw e;
}
// Days
try {
int maxDay = maxDayInMonthFor(_century, _year, _month);
int tempDay = (_day > maxDay) ? maxDay : _day;
// how to handle day < 1????this makes sense only if we create a new
// dateTime type (rare situation)
tempDay = tempDay + sign * duration.getDay() + carry;
while (true) {
if (tempDay < 1) {
tempDay = (short) (tempDay + maxDayInMonthFor(_century, _year, _month - 1));
this.setDay((short) tempDay);
carry = -1;
} else if (tempDay > maxDay) {
tempDay = (short) (tempDay - (short) maxDay);
carry = 1;
} else break;
try {
temp = _month + carry;
this.setMonth((short) (modulo(temp - 1, 12) + 1));
temp = fQuotient(temp - 1, 12);
temp = this.getCentury() * 100 + this.getYear() + temp;
short century = (short) (temp / 100);
temp = temp % 100;
this.setCentury(century);
this.setYear((short) temp);
} catch (OperationNotSupportedException e) {
// --if there is no Year field in the date/time datatypes
// --we do nothing else we throw a runTime exception
if (!((this instanceof Time) || (this instanceof GMonthDay))) throw e;
}
}
this.setDay((short) tempDay);
} catch (OperationNotSupportedException e) {
// if there is no Month field in the date/time datatypes
// we do nothing else we throw a runTime exception
if (!((this instanceof Time) || (this instanceof GYearMonth) || (this instanceof GMonth)))
throw e;
}
} // addDuration
