ical4j异常日历必须至少包含一个组件

Question

Im trying to create and save an ics using ical4j

When i run the following code, I get a calendar must contain at least one component.. how do I attach a component to my calendar, or an event to my calendar...

Exception in thread "main" net.fortuna.ical4j.model.ValidationException: Calendar must contain at least one component

    Calendar calendar = new Calendar();
    calendar.getProperties().add(new ProdId("-//Tyler Eans//iCal4j 1.0//EN"));
    calendar.getProperties().add(Version.VERSION_2_0);
    calendar.getProperties().add(CalScale.GREGORIAN);

    java.util.Calendar cal = java.util.Calendar.getInstance();
    cal.set(java.util.Calendar.MONTH, java.util.Calendar.DECEMBER);
    cal.set(java.util.Calendar.DAY_OF_MONTH, 25);

    VEvent christmas = new VEvent(new Date(cal.getTime()), "Christmas Day");
    // initialise as an all-day event..
    christmas.getProperties().getProperty(Property.DTSTART).getParameters().add(Value.DATE);

    FileOutputStream fout = new FileOutputStream("mycalendar.ics");

    CalendarOutputter outputter = new CalendarOutputter();
    outputter.output(calendar, fout);

Answer 1

只需在输出之前添加此行：

calendar.getComponents().add(christmas);