Uploading a large file in multipart using OkHttp

Get OkHttp 2.1, and use MultipartBuilder.addFormDataPart() which takes the filename as a parameter.

       /**
         * Upload Image
         *
         * @param memberId
         * @param sourceImageFile
         * @return
         */
        public static JSONObject uploadImage(String memberId, String sourceImageFile) {
    
            try {
                File sourceFile = new File(sourceImageFile);
    
                Log.d(TAG, "File...::::" + sourceFile + " : " + sourceFile.exists());
             //Determining the media type        
             final MediaType MEDIA_TYPE = sourceImageFile.endsWith("png") ? 

                MediaType.parse("image/png") : MediaType.parse("image/jpeg");
                
    
                RequestBody requestBody = new MultipartBuilder()
                        .type(MultipartBuilder.FORM)
                        .addFormDataPart("member_id", memberId)
                        .addFormDataPart("file", "profile.png", RequestBody.create(MEDIA_TYPE, sourceFile))
                        .build();
    
                Request request = new Request.Builder()
                        .url(URL_UPLOAD_IMAGE)
                        .post(requestBody)
                        .build();
    
                OkHttpClient client = new OkHttpClient();
                Response response = client.newCall(request).execute();
                return new JSONObject(response.body().string());
    
            } catch (UnknownHostException | UnsupportedEncodingException e) {
                Log.e(TAG, "Error: " + e.getLocalizedMessage());
            } catch (Exception e) {
                Log.e(TAG, "Other Error: " + e.getLocalizedMessage());
            }
            return null;
        }

#Edited for okhttp3:

compile 'com.squareup.okhttp3:okhttp:3.4.1'

RequestBody replaced by:

RequestBody requestBody = new MultipartBody.Builder()
                    .setType(MultipartBody.FORM)
                    .addFormDataPart("uploaded_file", filename, RequestBody.create(MEDIA_TYPE_PNG, sourceFile))
                    .addFormDataPart("result", "my_image")
                    .build();

#Uploaded Demo on GITHUB: ##I have added my answer for Multiple Image Upload :)

From the OkHttp Recipes page, this code uploads an image to Imgur:

private static final String IMGUR_CLIENT_ID = "...";
private static final MediaType MEDIA_TYPE_PNG = MediaType.parse("image/png");

private final OkHttpClient client = new OkHttpClient();

public void run() throws Exception {
  // Use the imgur image upload API as documented at https://api.imgur.com/endpoints/image
  RequestBody requestBody = new MultipartBuilder()
      .type(MultipartBuilder.FORM)
      .addPart(
          Headers.of("Content-Disposition", "form-data; name=\"title\""),
          RequestBody.create(null, "Square Logo"))
      .addPart(
          Headers.of("Content-Disposition", "form-data; name=\"image\""),
          RequestBody.create(MEDIA_TYPE_PNG, new File("website/static/logo-square.png")))
      .build();

  Request request = new Request.Builder()
      .header("Authorization", "Client-ID " + IMGUR_CLIENT_ID)
      .url("https://api.imgur.com/3/image")
      .post(requestBody)
      .build();

  Response response = client.newCall(request).execute();
  if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

  System.out.println(response.body().string());
}

You'll need to adapt this to S3, but the classes you need should be the same.