SAP JAM - ODATA - Create Event with Attachment

Hi guys,

I'm trying to figure out, how to create an event with attachment.

Creating an event works so far.

(...)
HttpPost jamRequest = new HttpPost("/api/v1/OData/Groups('" + groupID + "')/UpcomingEvents");
(...)
and in the JSON file:

	String jsonToSend = "";
	jsonToSend += "{";
	jsonToSend += "\"Name\": \"" + eventName + "\",";
	jsonToSend += "\"StartAt\": \"" + startAt + "\",";
	jsonToSend += "\"EndAt\": \"" + endAt + "\"";
	jsonToSend += "}";
	
	StringEntity entity = new StringEntity(jsonToSend);		
	jamRequest.setEntity(entity);

But how to get the attachment here?

Then I thought maybee to first create Event, then create a ContentItem and then "link" both.

So next thing I tried out, was how to upload 'ContentItem':

Therefore I uploaded a "test.pdf"-file on the server in Folder "Events":

Upload File works:

(...)
HttpPost jamRequest = new HttpPost("/api/v1/OData/ContentItems");
	//Setting the request and response formats to json
	jamRequest.addHeader("Content-Type", "application/pdf");
	jamRequest.addHeader("Slug", "test.pdf");
	jamRequest.addHeader("Accept", "application/json");
		
	String fileDesc = request.getParameter("slug");
	String contentType = "application/pdf";
	String file = request.getParameter("file");	


	String root = getServletContext().getRealPath("/");
    File path = new File(root + "/Events");
    File filepath = new File(path + "/" + "test.pdf");
	FileEntity inputData = new FileEntity(filepath,contentType);	
	jamRequest.setEntity(inputData);
(...)

Is it possible to link my ContentItem with a Event.

Or maybee create an Event directly with attachment?

The SAP JAM OData API is not very helpful here and I didn't found any helpful page anywhere. I found "SAP_Jam_OData_HCP" on github which were nice for a good start, but there ar no examples for events :/

Thank you!