How to send a “multipart/form-data” POST in Android with Volley

Question

Has anyone been able to accomplish sending a multipart/form-data POST in Android with Volley yet? I have had no success trying to upload an image/png

Answer 1

As mentioned in the presentation at the I/O (about 4:05), Volley "is terrible" for large payloads. As I understand it that means not to use Volley for receiving/sending (big) files. Looking at the code it seems that it is not even designed to handle multipart form data (e.g. Request.java has getBodyContentType() with hardcoded "application/x-www-form-urlencoded"; HttpClientStack::createHttpRequest() can handle only byte[], etc...). Probably you will be able to create implementation that can handle multipart but If I were you I will just use HttpClient directly with MultipartEntity like:

    HttpPost req = new HttpPost(composeTargetUrl());
    MultipartEntity entity = new MultipartEntity();
    entity.addPart(POST_IMAGE_VAR_NAME, new FileBody(toUpload));
    try {
        entity.addPart(POST_SESSION_VAR_NAME, new StringBody(uploadSessionId));
    } catch (UnsupportedEncodingException e) {
        throw new RuntimeException(e);
    }
    req.setEntity(entity);

You may need newer HttpClient (i.e. not the built-in) or even better, use Volley with newer HttpClient