RFC5545。同时计算RRULE和EXDATE (EXRULE)的事件发生情况开发者社区

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import org.dmfs.rfc5545.DateTime;
import org.dmfs.rfc5545.recurrenceset.RecurrenceRuleAdapter;
import org.dmfs.rfc5545.recurrenceset.RecurrenceSet;
import org.dmfs.rfc5545.recurrenceset.RecurrenceSetIterator;
@Test
public void testSpecial() throws InvalidRecurrenceRuleException {
    RecurrenceRule recurrenceRule = new RecurrenceRule("FREQ=YEARLY;BYMONTHDAY=23;BYMONTH=5;COUNT=3");
    RecurrenceRuleIterator it = recurrenceRule.iterator(DateTime.nowAndHere());
    int maxInstances = 10; // limit instances for rules that recur forever
    while (it.hasNext() && (!recurrenceRule.isInfinite() || maxInstances-- > 0)) {
        DateTime nextInstance = it.nextDateTime();
        // do something with nextInstance
        System.out.println(nextInstance);
}

import com.google.ical.compat.jodatime.LocalDateIterable;
import com.google.ical.compat.jodatime.LocalDateIterator;
import com.google.ical.compat.jodatime.LocalDateIteratorFactory;
import com.google.ical.values.RRule;
@Test
public void test() throws ParseException {
    String sRule = "RRULE:FREQ=YEARLY;COUNT=3;INTERVAL=2;BYMONTH=5;BYMONTHDAY=22,23,24,25,26,27,28;BYDAY=MO";
    LocalDateIterable localDateIterable = LocalDateIteratorFactory
            .createLocalDateIterable(sRule, org.joda.time.LocalDate.now(), true);
    LocalDateIterator iterator = localDateIterable.iterator();
    while (iterator.hasNext()) {
        System.out.println(iterator.next());
}

// note: recurrence expansion takes place in a specific time zone
TimeZone tz = TimeZone.getDefault();
// the start of the recurring event
DateTime start = new DateTime(tz, 2017, 5 - 1 /* zero based */, 23, 12, 0, 0);
// parse the RRULE
RecurrenceRule recurrenceRule = new RecurrenceRule("FREQ=YEARLY;BYMONTHDAY=23;BYMONTH=5;COUNT=30");
// parse the EXRULE (in this case every 3rd instance of the RRULE)
RecurrenceRule exceptionRule = new RecurrenceRule("FREQ=YEARLY;INTERVAL=3;BYMONTHDAY=23;BYMONTH=5;COUNT=10");
// create an empty RecurrenceSet
// a recurrence set is the set of all actual instance of a recurring event and may consist of multiple instance and excludes sources 
RecurrenceSet recurrenceSet = new RecurrenceSet();
// add the instances of the RRULE
recurrenceSet.addInstances(new RecurrenceRuleAdapter(recurrenceRule));
// exclude the instances of the EXRULE
recurrenceSet.addExceptions(new RecurrenceRuleAdapter(exceptionRule));
RecurrenceSetIterator recurrenceSetIterator = recurrenceSet.iterator(start.getTimeZone(), start.getTimestamp());
int maxInstances = 10; // limit instances for rules that recur forever
// iterate as long as the recurrence set still has instances
while (recurrenceSetIterator.hasNext() && (!recurrenceRule.isInfinite() || maxInstances-- > 0))
    // get the next instance of the recurrence set
    DateTime nextInstance = new DateTime(start.getTimeZone(), recurrenceSetIterator.next());
    // do something with nextInstance

问 RFC5545。同时计算RRULE和EXDATE (EXRULE)的事件发生情况 EN

回答 1

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