Final solution provided by @user2662369
@future(callout=true)
public static void fileUploadCallout(string idStr)
{
string Endpoint = 'https:********';
string xAPIKey = '***********';
string verticalId = '*******';
string callbackURL = '**************';
List<contentversion> cvList = new List<contentversion>();
cvList = [select id, title, ContentDocumentId, FileExtension, versionData from contentversion where Id = :idStr limit 1];
System.debug('Callout Log 1:' + cvList);
if(!cvList.isEmpty())
{
//form fileName with cv ID
string fileName = cvList[0].Id;
if(cvList[0].FileExtension!=null && cvList[0].FileExtension!='')
{
fileName = fileName + '.' + cvList[0].FileExtension;
}
System.debug('Callout Log 2:' + fileName);
//callout ePOR service
string contentType = EinsteinVision_HttpBodyPart.GetContentType();
// Compose the form
string form64 = '';
//******This was the boundary I was missing****
form64 += EinsteinVision_HttpBodyPart.WriteBoundary();
form64 += EinsteinVision_HttpBodyPart.WriteBlobBodyParameter('file', EncodingUtil.base64Encode(cvList[0].versionData), fileName);
blob formBlob = EncodingUtil.base64Decode(form64);
string contentLength = string.valueOf(formBlob.size());
System.debug('Callout Log 3:' + formBlob.size());
if(formBlob.size()>12000000)
{
//this a "public class CustomException extends Exception{}"
throw new CustomException('File size limit is 12 MBytes');
}
else
{
HttpRequest req = new HttpRequest();
req.setMethod('POST');
req.setEndpoint(Endpoint);
req.setBodyAsBlob(formBlob);
req.setHeader('apiKey', xAPIKey);
req.setHeader('vertid', verticalId);
req.setHeader('callback', callbackURL);
req.setHeader('Connection', 'keep-alive');
req.setHeader('Content-Length', contentLength);
req.setHeader('Content-Type', contentType);
req.setTimeout(120000);
Http http =new Http();
HTTPResponse res = http.send(req);
System.debug('Callout Log 4:' + res.getStatusCode());
System.debug('Callout Log 5:' + String.valueof(res.getbody()));
string responseStatusCode = String.valueof(res.getStatusCode());
string responseBody = String.valueof(res.getbody());
}
}
}
