You question is very oracle specific, so I am not sure if you get a full answer here.
Things you should check:
Authentication, your browser is likely authenticated to Jive, your app server making the call won't be. In that case the response will be a 401 with empty payload
Jive adds a security header (see Throw allowIllegalResourceCall to the Curb is True!) to its rest responses, which will throw off any methods that expect a valid Json payload
Finally, use something like Fiddler to see what calls are actually being made between oracle and Jive