如何使用@MultiPart将多个图像/文件与@Body一起上载到改装中

Question

我需要使用@POST-in-reformation提交大数据（嵌套的json对象）以及多个图像/文件。

一种简单/hacky的方法是将图像转换为base 64字符串

{
  "id": "id12",
  "bar": {
    "id": "id1",
    "name": "asd"
  }
} .....

但是如何使用@Multipart发送身体和图像。

@Multipart
@POST("api/upload")
Observable<SubmitResponse> submitData(@Body Foo foo, @Part MultipartBody.Part[] files);

class Foo {

    @SerializedName("book_id")
    @Expose
    private String book_id;
    @SerializedName("bar")
    @Expose
    private Bar anotherBodyinsideFoo;

}

上述方法引发错误：@Body参数不能用于表单或多部分编码。

就如何在Retrofit中上传多个文件以及请求正文（@body Foo）提出建议。

Answer 1

请检查以下代码，以便使用改装上载多个图像

@POST(UPLOAD_EVENT)
    Call<EventResponse> uploadEvent(@Header("Authorization") String auth, @Body RequestBody body);

 MultipartBody.Builder builder = new MultipartBody.Builder();
    builder.setType(MultipartBody.FORM);
    builder.addFormDataPart("event_name", eventName);
    builder.addFormDataPart("location", loacation);
    builder.addFormDataPart("longitude", longitude);
    builder.addFormDataPart("latitude", latitude);
    builder.addFormDataPart("is_private", isPublic);
    builder.addFormDataPart("caption", caption);
    RequestBody requestBody = RequestBody.create(MediaType.parse("multipart/form-data"), coverImage);
    builder.addFormDataPart("cover_image", coverImage.getName(), requestBody);
    RequestBody requestBody1 = null;

    for (int i = 0, size = eventFiles.size(); i < size; i++) {
        requestBody1 = RequestBody.create(MediaType.parse("multipart/form-data"), eventFiles.get(i));
        builder.addFormDataPart("album_images" + "[" + i + "]", eventFiles.get(i).getName(), requestBody1);
    }
    RequestBody finalRequestBody = builder.build();

    final Retrofit retrofit = new Retrofit.Builder()
            .baseUrl(RestClient.ROOT)
            .addConverterFactory(GsonConverterFactory.create())
            .build();
    RestClient.NetworkCall networkCall = retrofit.create(RestClient.NetworkCall.class);

    Call<EventResponse> response = networkCall.uploadEvent(Prefs.getAuth(App.getContext()), finalRequestBody);

    response.enqueue(new Callback<EventResponse>() {
        @Override
        public void onResponse(Call<EventResponse> call, Response<EventResponse> response) {
            NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
            notificationManager.cancel(MY_NOTIFICATION_ID);
            if (response.code() == Constant.SUCCESS_STATUS) {

                if (response.body() != null) {
                    sendBroadcast(new Intent(Constant.REFRESH_FEEDS));
                    Log.e("Success", "Success");
                }
            } else {
                Converter<ResponseBody, EventResponse> converter =
                        retrofit.responseBodyConverter(EventResponse.class, new Annotation[0]);
                try {
                    if (response.errorBody() != null) {
                        EventResponse errorResponse = converter.convert(response.errorBody());
                        Log.e("Failure", "Failure");
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        @Override
        public void onFailure(Call<EventResponse> call, Throwable t) {
            NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
            notificationManager.cancel(MY_NOTIFICATION_ID);
            Log.e("Failure", "Failure");
        }
    });