I'm wondering if anyone can tell me the proper syntax & formatting for a service account to send a POST Object to bucket request? I'm attempting it programmatically using the HttpComponents library. I manage to get a token from my GoogleCredential, but every time I construct the POST request, I get:

HTTP/1.1 403 Forbidden

<?xml version='1.0' encoding='UTF-8'?><Error><Code>AccessDenied</Code><Message>Access denied.</Message><Details>bucket-name</Details></Error>

The Google documentation that describes the request methods, mentions posting using html forms, but I'm hoping that wasn't suggesting the ONLY way to get the job done. I know that HttpComponents has a way to explicitly create form data by using UrlEncodedFormEntity, but it doesn't support multipart data. Which is why I went with using the MultipartEntity class. My code is below:

MultipartEntity entity = new MultipartEntity( HttpMultipartMode.BROWSER_COMPATIBLE );
String token = credential.getAccessToken();
entity.addPart("Authorization", new StringBody("OAuth " + token));
String date = formatDate(new Date());
entity.addPart("Date", new StringBody(date));
entity.addPart("Content-Encoding", new StringBody("UTF-8"));
entity.addPart("Content-Type", new StringBody("multipart/form-data"));
entity.addPart("bucket", new StringBody(bucket));
entity.addPart("key", new StringBody("fileName"));
entity.addPart("success_action_redirect", new StringBody("/storage"));
File uploadFile = new File("pathToFile");
FileBody fileBody = new FileBody(uploadFile, "text/xml");
entity.addPart("file", fileBody);
httppost.setEntity(entity);
System.out.println("Posting URI = "+httppost.toString());
HttpResponse response = client.execute(httppost);
HttpEntity resp_entity = response.getEntity();

As I mentioned, I am able to get an actual token, so I'm pretty sure the problem is in how I've formed the request as opposed to not being properly authenticated.

Keep in mind:

1. This is being performed by a service account.
2. Which means that it does have Read/Write access

Thanks for reading, and I appreciate any help!