Making a multipart/form-data POST request

[Jake Rockwell]

For an Android app I have to make a POST request with the "Content-Type" set to multipart/form-data, since I need to support the upload of files. However, I am unable to figure out how to do this. I think I need to use the classes MultipartContent and Part, but I do not know the correct way to use them.

I did manage to successfully use a regular "application/json" based POST as follows:

String requestUrl = "http://www.someurl.com/api/user/create";

HttpContent content;

JSONObject defaultJsonObject = new JSONObject();

defaultJsonObject.put("firstname", "Testia");

defaultJsonObject.put("lastname", "Test");

defaultJsonObject.put("nickname", "Tes");

defaultJsonObject.put("dob", "1987-12-30");

defaultJsonObject.put("gender", "f");

content = ByteArrayContent.fromString("application/json", defaultJsonObject.toString());

HttpRequest request = getHttpRequestFactory()

.buildPostRequest(new GenericUrl( requestUrl ), content);

request.setParser( new JacksonFactory().createJsonObjectParser() );

HttpResponse response = request.execute();

How should I adapt above code to send the request as a multipart/form-data request? Furthermore, how should I extend the request to allow the sending of files? 

Thank you in advance!