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

I might be wrong on this but I think you need to implement your own com.android.volley.toolbox.HttpStack for this because the default ones (HurlStack if version > Gingerbread or HttpClientStack) don't deal with multipart/form-data.

Edit:

And indeed I was wrong. I was able to do it using MultipartEntity in Request like this:

public class MultipartRequest extends Request {

    private MultipartEntity entity = new MultipartEntity();

    private static final String FILE_PART_NAME = "file";
    private static final String STRING_PART_NAME = "text";

    private final Response.Listener mListener;
    private final File mFilePart;
    private final String mStringPart;

    public MultipartRequest(String url, Response.ErrorListener errorListener, Response.Listener listener, File file, String stringPart)
    {
        super(Method.POST, url, errorListener);

        mListener = listener;
        mFilePart = file;
        mStringPart = stringPart;
        buildMultipartEntity();
    }

    private void buildMultipartEntity()
    {
        entity.addPart(FILE_PART_NAME, new FileBody(mFilePart));
        try
        {
            entity.addPart(STRING_PART_NAME, new StringBody(mStringPart));
        }
        catch (UnsupportedEncodingException e)
        {
            VolleyLog.e("UnsupportedEncodingException");
        }
    }

    @Override
    public String getBodyContentType()
    {
        return entity.getContentType().getValue();
    }

    @Override
    public byte[] getBody() throws AuthFailureError
    {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        try
        {
            entity.writeTo(bos);
        }
        catch (IOException e)
        {
            VolleyLog.e("IOException writing to ByteArrayOutputStream");
        }
        return bos.toByteArray();
    }

    @Override
    protected Response parseNetworkResponse(NetworkResponse response)
    {
        return Response.success("Uploaded", getCacheEntry());
    }

    @Override
    protected void deliverResponse(String response)
    {
        mListener.onResponse(response);
    }
}

It's pretty raw but I tried it with an image and a simple string and it works. The response is a placeholder, doesn't make much sense to return a Response String in this case. I had problems using apache httpmime to use MultipartEntity so I used this https://code.google.com/p/httpclientandroidlib/ don't know if there's a better way. Hope it helps.

Edit

You can use httpmime without using httpclientandroidlib, the only dependency is httpcore.