使用 Retrofit 2.0 上传多个文件

Question

我目前正在处理应用程序的一部分，用户需要从图库中选择一些图像，然后将这些图像上传到服务器。对于上传，我使用的是使用 multipart 的改造 2.0。

根据资源 https://futurestud.io/blog/retrofit-2-how-to-upload-files-to-server 我在仅使用一个文件时设法成功实现了它，但是我希望在一个会话中所有用户选择的图像都上传到服务器。

环顾四周，我发现 "Retrofit" multiple images attached in one multipart request 那里讨论了 @partmap 注释，这似乎是正确的匹配，但是我不明白我将如何迭代我需要上传的图像？

谁能告诉我正确的实施方式？

还检查了： 1. 2.Upload multiple image with same name as array Retrofit 2.0.0-beta2

Answer 1

我只是想解决一个类似的案例，但我有大量的文件。

我试过用循环来解决它：

recordsDirectory.mkdirs();
final File[] list_files = recordsDirectory.listFiles();
int cont = list_files.length;
for (int i = 0; i < cont; i++) {
    final File ref_file = list_files[i];
    String source_filepath = ref_file.getPath();
    RequestBody requestBody =
                RequestBody.create(MediaType.parse("multipart/form-data"), ref_file);
    Call<DeliveryResponse> call = apiService.upload(requestBody, description);
    call.enqueue(new Callback<DeliveryResponse>() {
        @Override
        public void onResponse(Response<DeliveryResponse> response, Retrofit retrofit) {
            Log.v(TAG, "[" + TAG + "] Upload success. status: " + response.toString());
            DeliveryResponse deliveryResponse = response.body();
            Log.v(TAG, "response code: " + deliveryResponse.mStatus);
            Log.v(TAG, "response code: " + response.code());
            Log.v(TAG, "ref_file: " + ref_file.getPath());
            if (response.isSuccess()) {
                Log.i(TAG, "[" + TAG + "] The server has response with a status distinct to 200.");
            }
            else {
                if (deliveryResponse.mStatus == 1) {
                    Log.i(TAG, "[" + TAG + "] The server has response with 1 as status.");
                    boolean deleted = ref_file.delete();                        
                } else {
                    Log.i(TAG, "[" + TAG + "] The server has response with 0 as status.");
                }
            }
        }

        @Override
        public void onFailure(Throwable t) {
            Log.e("Upload", t.getMessage());
        }
    });
}

/***********************************************
 RETROFIT API
 ************************************************/
public interface MyApiEndpointInterface {
    @Multipart
    @POST("/elderbask/api/sensors/accelerometer")
    Call<DeliveryResponse> upload(
        @Part("myfile\"; filename=\"image.png\" ") RequestBody file,
        @Part("description") String description
    );
}

public static class DeliveryResponse {

    @SerializedName("status")
    int mStatus;

    public DeliveryResponse(int status) {
        this.mStatus = status;
    }

    public String toString(){
        return "mStatus: " + this.mStatus;
    }

}

但是这个解决方案并不像我预期的那样有效。我有很多超时异常，错误的硬编码文件名非常糟糕。

Answer 2

由于我没有设法使用改造解决问题，所以我最终使用了 okhttp 库，它给了我我需要的东西，这里是我使用的代码示例，我希望它能帮助别人

构建请求正文：

                    okhttp3.RequestBody requestBody = new MultipartBody.Builder()
                        .setType(MultipartBody.FORM)
                        .addPart(okhttp3.Headers.of("Content-Disposition:", "form-data; name=\"myfile\"; filename=\"image" + ImageNumber + ".jpg\""),
                                okhttp3.RequestBody.create(MEDIA_TYPE_JPG, new File(ImagePath)))
                        .build();

准备请求：

                         request = new okhttp3.Request.Builder()
                            .header("Authorization", "Client-ID " )
                            .url(YOUR URL)
                            .post(requestBody)
                            .build();

启动与服务器的连接：

                    try {
                    okhttp3.Response response = client.newCall(request).execute();
                    if (!response.isSuccessful())
                        throw new IOException("Unexpected code " + response);
                        System.out.println(response.body().string());
                } catch (IOException e) {
                    e.printStackTrace();
                }

Answer 3

哇哦！我做到了，你可以像我一样尝试这个（改造 2）

    //1. What We Need From Server ( upload.php Script )
    public class FromServer {
        String result;
    }

    //2. Which Interface To Communicate Our upload.php Script?
    public interface ServerAPI {

        @Multipart
        @POST("upload.php")//Our Destination PHP Script
        Call<List<FromServer>> upload(
                @Part("file_name") String file_name,
                @Part("file") RequestBody file);

         Retrofit retrofit =
                new Retrofit.Builder()
                        .baseUrl("http://192.168.43.135/retro/") // REMEMBER TO END with /
                        .addConverterFactory(GsonConverterFactory.create())
                 .build();
    }


    //3. How To Upload
    private void upload(){

            ServerAPI api = ServerAPI.retrofit.create(ServerAPI.class);

            File from_phone = FileUtils.getFile(Environment.getExternalStorageDirectory()+"/aa.jpg"); //org.apache.commons.io.FileUtils
            RequestBody to_server = RequestBody.create(MediaType.parse("multipart/form-data"), from_phone);

            api.upload(from_phone.getName(),to_server).enqueue(new Callback<List<FromServer>>() {
                @Override
                public void onResponse(Call<List<FromServer>> call, Response<List<FromServer>> response) {
                    Toast.makeText(MainActivity.this, response.body().get(0).result, Toast.LENGTH_SHORT).show();
                }
                @Override
                public void onFailure(Call<List<FromServer>> call, Throwable t) { }
            });


         }

//4. upload.php
<?php

    $pic = $_POST['file_name'];

    $pic = str_replace("\"", "", $pic); //REMOVE " from file name

    $f = fopen($pic, "w");
    fwrite($f,$_POST['file']);
    fclose($f);

    $arr[] = array("result"=>"Done");
    print(json_encode($arr));
?>

使用 Retrofit 2.0 上传多个文件

multiple file upload using retrofit 2.0

php

android

file-upload

multipart

retrofit2