class to upload to S3

gistfile1.java

public class AWSClient implements AWSApi {
  private final AWSApi awsApi;
  @Inject OkHttpClient client;
  @Inject ErrorHandler errorHandler;

  public AWSClient(final DottieApplication application) {
    application.inject(this);
    RestAdapter restAdapter = new RestAdapter.Builder().setClient(new OkClient(client))
        .setEndpoint(Constants.AWS_ENDPOINT)
        .setErrorHandler(errorHandler)
        .build();

    awsApi = restAdapter.create(AWSApi.class);
  }

  @Override public Observable<Response> uploadImage(@Part("key") TypedString key,
      @Part("acl") TypedString acl, @Part("AWSAccessKeyId") TypedString awsAccessKeyId,
      @Part("Policy") TypedString policy, @Part("Signature") TypedString signature,
      @Part("Content-Type") TypedString contentType, @Part("file") TypedFile file) {

    return awsApi.uploadImage(key, acl, awsAccessKeyId, policy, signature, contentType, file);
  }

  public Observable<String> uploadJpeg(TypedString fileName, TypedFile file) {
    return uploadImage(fileName, new TypedString("public-read"),
        new TypedString(Constants.AWS_ACCESS_KEY), new TypedString(Constants.AWS_POLICY),
        new TypedString(Constants.AWS_SIGNATURE), new TypedString("image/jpeg"), file).flatMap(
        new Func1<Response, Observable<String>>() {

          @Override public Observable<String> call(Response response) {
            List<Header> headers = response.getHeaders();
            String locationHeader = null;
            for (Header header : headers) {
              if (header.getName() != null && header.getName().contentEquals("Location")) {
                // Uploaded File Url
                locationHeader = header.getValue();
                break;
              }
            }

            final String fileUrl = locationHeader;
            return Observable.create(new Observable.OnSubscribe<String>() {
              @Override public void call(Subscriber<? super String> subscriber) {
                if (TextUtils.isEmpty(fileUrl)) {
                  subscriber.onError(new Exception());
                  return;
                }

                subscriber.onNext(fileUrl);
                subscriber.onCompleted();
              }
            });
          }
        }

    );
  }
}

Hector: Do you have code for AWSApi? Thanks!