Streaming API

[marsianer]

Is it possible to do event-based processing so that the entire calendar does not have to be loaded into memory?
Unfortunately, my calendar contains many attachments (GPX recordings of workouts) that make the calendar grow.
On my Android smartphone, this unfortunately leads to an OOM termination.

DAVx⁵ / OOM termination

This method loads the entire calendar into memory.

FileInputStream fin = new FileInputStream("calendar.ics"); 
CalendarBuilder builder = new CalendarBuilder();
Calendar calendar = builder.build(fin);

Is there a method like this?

File file = new File("calendar.ics");
CalendarReader calendarReader = new CalendarReader(file);
Calendar calendar;
while ((calendar = calendarReader.readNext()) != null){
  // ...
}
calendarReader.close();

[benfortuna]

Yes, if you want to implement streaming, or even conditional parsing (e.g. skip large attachments), you can implement your own ContentHandler.

This is provided to the CalendarParser, to process each line. The CalendarBuilder just encapsulates a DefaultContentHandler and CalendarParser for convenience.

File file = new File("calendar.ics");
// unfolding reader handles split lines..
UnfoldingReader calendarReader = new UnfoldingReader(file);

CalendarParser parser = CalendarParserFactory.getInstance().get();
ContentHandler handler = ...

parser.parse(calendarReader, handler);