IBM Domino xpage - parse iCalendar summary with new lines manually/ical4j - xpages

Question

So far I was parsing the NotesCalendarEntry ics manually and overwriting certain properties, and it worked fine. Today i stumbled upon a problem, where a long summary name of the appointment gets split into multiple lines, and my parsing goes wrong, it replaces the part up to the first line break and the old part is still there.
Here's how I do this "parsing":
NotesCalendarEntry calEntry = cal.getEntryByUNID(apptuid);
String iCalE = calEntry.read();
StringBuilder sb = new StringBuilder(iCalE);
int StartIndex = iCalE.indexOf("BEGIN:VEVENT"); // care only about vevent
tmpIndex = sb.indexOf("SUMMARY:") + 8;
LineBreakIndex = sb.indexOf(Character.toString('\n'), tmpIndex);
if(sb.charAt(LineBreakIndex-1) == '\r') // take \r\n into account if exists
LineBreakIndex--;
sb.delete(tmpIndex, LineBreakIndex); // delete old content
sb.insert(tmpIndex, subject); // put my new content
It works when line breaks are where they are supposed to be, but somehow with long summary name, line breaks are put into the summary (not literal \r\n characters, but real line breaks).
I split the iCalE string by \r\n and got this (only a part obviously):
SEQUENCE:6
ATTENDEE;ROLE=CHAIR;PARTSTAT=ACCEPTED;CN="test/Test";RSVP=FALSE:
mailto:test#test.test
ATTENDEE;CUTYPE=ROOM;ROLE=REQ-PARTICIPANT;PARTSTAT=ACCEPTED
;CN="Room 2/Test";RSVP=TRUE:mailto:room2#test.test
CLASS:PUBLIC
DESCRIPTION:Test description\n
SUMMARY:Very long name asdjkasjdklsjlasdjlasjljraoisjroiasjroiasjoriasoiruasoiruoai Mee
ting long name
LOCATION:Room 2/Test
ORGANIZER;CN="test/Test":mailto:test#test.test
Each line is one array element from iCalE.split("\\r\\n");. As you can see, the Summary field got split into 2 lines, and a space was added after the line break.
Now I have no idea how to parse this correctly, I thought about finding the index of next : instead of a new line break, and then finding the first line break before that : character, but that wouldn't work if the summary also contained a : after the injected line-break, and also wouldn't work on fields like that ORGANIZER;CN= as it doesn't use : but ;
I tried importing external ical4j jar into my xpage to overcome this problem, and while everything is recognized in Domino Designer it resulted in lots of NoClassDefFound exceptions after trying to reach my xpage service, despite the jars being in the build path and all.
java.lang.NoClassDefFoundError: net.fortuna.ical4j.data.CalendarBuilder
How can I safely parse this manually, or how can I properly import ical4j jar to my xpage? I just want to modify 3 fields, the DTSTART, DTEND and SUMMARY, with the dates I had no problems so far. Fields like Description are using literal \n string to mark new lines, it should be the same in other fields...
Update
So I have read more about iCalendar, and it seems that there is a standard for this called line folds, these are crlf line endings followed by a space. I made a while loop checking until the last line-break not followed by a space, and it works great so far. Will use this unless there's a better solution (ical4j is one, but I can't get it working with Domino)