AFHttpSessionManager - Multipart POST causing org.codehaus.jackson.JsonParseException - jackson

Question

Am trying to use AFNetworking 2's AFHTTPSessionManager to post pdf content to my web service. I have subclassed AFHTTPSessionManager and set request and response serializers to the corresponding AFJsonXXXSerializer. However when I POST the form data as a multi part request, I get a JsonParseException. Am pretty sure this is a straight forward use case and I might be missing something. Pls help, Thanks in advance !
[accessMgr postDataToURL:#"objects-d2" usingParams:nil fileData:imageData andDelegate:self];
which calls the below method to POST
-(void) postDataToURL:(NSString *) urlString usingParams:(id)parameters fileData: (NSData *)fileData andDelegate:(id<RemoteAccessDelegate>) remoteDelegate
{
//RESTSessionManager extends AFHTTPSessionMaanger
RESTSessionManager *manager = [self getManager:remoteDelegate];
[manager POST:urlString parameters: parameters constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
[formData appendPartWithFileData:fileData name:#"content" fileName:#"test.pdf" mimeType:#"application/pdf"];
The request goes with the following headers and the form data
POST /d2fs/repositories/ls67sp2/objects-d2 HTTP/1.1
Host: localhost:8080
Content-Type: multipart/form-data; boundary=Boundary+422AF86226B68040
Connection: keep-alive
Transfer-Encoding: Chunked
Accept: application/json
User-Agent: IIG Mobile/1.1 (iPad Simulator; iOS 7.1; Scale/2.00)
Accept-Language: en;q=1, fr;q=0.9, de;q=0.8, zh-Hans;q=0.7, zh-Hant;q=0.6, ja;q=0.5
Authorization: Basic bHNhZG1pbjpsc2FkbWlu
Accept-Encoding: gzip, deflate
--Boundary+422AF86226B68040
Content-Disposition: form-data; name="content"; filename="test.pdf"
Content-Type: application/pdf
%PDF-1.3
%ƒÂÚÂÎßÛ†–ƒ∆
<more file content>
I have verified that the trailing boundary is also set. The response am getting from my web service is
{
"status": 400,
"code": "E_INPUT_ILLEGAL_ARGUMENTS",
"message": "There are illegal arguments provided.",
"details": "org.codehaus.jackson.JsonParseException: Unexpected character ('%' (code 37)): expected a valid value (number, String, array, object, 'true', 'false' or 'null')\n at [Source: org.apache.commons.fileupload.MultipartStream$ItemInputStream#22a5cdce; line: 1, column: 2];Unexpected character ('%' (code 37)): expected a valid value (number, String, array, object, 'true', 'false' or 'null')\n at [Source: org.apache.commons.fileupload.MultipartStream$ItemInputStream#22a5cdce; line: 1, column: 2]"
}

Answer 1

I was able to resolve this issue today. I had to append a json object which was metadata about the object before appending the file data and the upload worked as a charm ! Thanks.
[formData appendPartWithFormData:data name:#"object"];
[formData appendPartWithFileData:fileData name:#"content" fileName:#"test.pdf" mimeType:#"application/pdf"];