public Date calculateGreatestMatchOnOrBefore(Date that) {
if (equals(UNSPECIFIED)) // Performance improvement
return null;
GregorianCalendar gc = that.calculateGC();
if (year != UNSPECIFIED_YEAR && year < that.year) // Performance improvement
gc.add(Calendar.YEAR, year - that.year + 1);
if (!that.sameAs(MAXIMUM_DATE)) {
// Start a day ahead
gc.add(Calendar.DATE, 1);
}
Date date = new Date(gc);
boolean matched = matches(date);
while (true) {
gc.add(Calendar.DATE, -1);
date.resetTo(gc);
boolean b = matches(date);
if (!b && matched) matched = false;
else if (!matched && b) break;
if (date.sameAs(MINIMUM_DATE)) return null;
if (year != UNSPECIFIED_YEAR && year > date.year) // Performance improvement
return null;
}
return date;
}
public Date calculateLeastMatchOnOrBefore(Date that) {
if (equals(UNSPECIFIED)) // Performance improvement
return MINIMUM_DATE;
boolean matched = matches(that);
GregorianCalendar gc = that.calculateGC();
if (year != UNSPECIFIED_YEAR && year < that.year) // Performance improvement
gc.add(Calendar.YEAR, year - that.year + 1);
Date date = new Date(gc);
while (true) {
if (date.sameAs(MINIMUM_DATE)) return matched ? date : null;
gc.add(Calendar.DATE, -1);
date.resetTo(gc);
boolean b = matches(date);
if (b && !matched) matched = true;
else if (matched && !b) break;
if (year != UNSPECIFIED_YEAR && year > date.year) // Performance improvement
return null;
}
gc.add(Calendar.DATE, 1);
date.resetTo(gc);
return date;
}
private boolean matchDay(Date that) {
if (day == UNSPECIFIED_DAY) return true;
if (day == LAST_DAY_OF_MONTH) {
GregorianCalendar gc = that.calculateGC();
int lastDay = gc.getActualMaximum(Calendar.DATE);
return lastDay == that.day;
}
return day == that.day;
}
public Date calculateGreatestMatchOnOrAfter(Date that) {
if (equals(UNSPECIFIED)) return MAXIMUM_DATE;
boolean matched = matches(that);
GregorianCalendar gc = that.calculateGC();
Date date = new Date(gc);
while (true) {
gc.add(Calendar.DATE, 1);
date.resetTo(gc);
boolean b = matches(date);
if (b && !matched) matched = true;
else if (matched && !b) break;
if (date.sameAs(MAXIMUM_DATE)) return date;
}
gc.add(Calendar.DATE, -1);
date.resetTo(gc);
return date;
}
public Date calculateLeastMatchOnOrAfter(Date that) {
GregorianCalendar gc = that.calculateGC();
if (!that.sameAs(MINIMUM_DATE)) {
// Start a day behind
gc.add(Calendar.DATE, -1);
}
Date date = new Date(gc);
boolean matched = matches(date);
while (true) {
gc.add(Calendar.DATE, 1);
date.resetTo(gc);
boolean b = matches(date);
if (!b && matched) matched = false;
else if (!matched && b) break;
if (date.sameAs(MAXIMUM_DATE)) return null;
}
return date;
}
public static DayOfWeek forDate(Date date) {
GregorianCalendar gc = date.calculateGC();
int calendarDow = gc.get(Calendar.DAY_OF_WEEK);
return forCalendarDow(calendarDow);
}