使用 Retrofit 2 上传文件时出错

Question

我正在工作的系统有一个端点，它接收文件图片以设置用户的个人资料图片。如果我尝试通过 Postman 发送，一切正常：

当我尝试使用改造从我的应用程序上传它时，它总是失败。代码+堆栈跟踪如下：

服务器端代码：

begin
         user = User.find(doorkeeper_token.resource_owner_id)
         image = params[:image]
         attachment = {
             :filename => image[:filename],
             :type => image[:type],
             :headers => image[:head],
             :tempfile => image[:tempfile]
         }

         image_link = ""
         if params[:upload_type] == "profile"
           user.profile_image = ActionDispatch::Http::UploadedFile.new(attachment)
           image_link = get_image_path(user.id,params[:upload_type],"original",attachment[:filename])
           user.image_profile_original = get_image_path(user.id,params[:upload_type],"original",attachment[:filename])
           user.image_profile_large = get_image_path(user.id,params[:upload_type],"large",attachment[:filename])

---

 /*e22*/
    @Multipart
    @POST("user/upload_image")
    fun uploadUserImage(@Header("Authorization") authHeader: String,  @Part("upload_type") description: RequestBody, @Part file: MultipartBody.Part): Call<ResponseWrapper>

---

 fun uploadUserImage(image: Uri) {
        val source = File(image.path)
        val requestFile = RequestBody.create(MediaType.parse(getContext().contentResolver.getType(image)), source)
        val body = MultipartBody.Part.createFormData("image", "profile", requestFile)
        val description = RequestBody.create(okhttp3.MultipartBody.FORM, "profile")
        mMessenger.uploadUserImage(getAuthorizationHeader(), description, body).enqueue(ResponseWrapperCallback(EventCatalog.e0022))
    }

请求响应：

E/ResponseWrapperCallback: Failed processing request: profile: open failed: ENOENT (No such file or directory)
E/ResponseWrapperCallback: HTTP request mapped to event e0022 finished with error

---

编辑 1

我确实认为这个错误与 File 对象的实例化方式有关。如果我直接从 Uri 创建文件，它的真实路径似乎不会发送到服务器。我说由于上面的错误日志，它说它没有在检索到的设备的 Uri 上找到文件。我尝试从 Uri 中提取文件的真实路径，但是，服务器的错误日志已更改为：

/storage/emulated/0/Marvel/Media/Characters/Adam Warlock.jpeg: open failed: EACCES (Permission denied)

我用真实文件路径实例化 File 对象的方式是这样的：

   private fun getRealPathFromURI(contentURI: Uri): String {
        val result: String
        val cursor = getContext().contentResolver.query(contentURI, null, null, null, null)
        if (cursor == null) {
            result = contentURI.path
        } else {
            cursor.moveToFirst()
            val idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA)
            result = cursor.getString(idx)
            cursor.close()
        }
        return result
    }

//....

val source = File(getRealPathFromURI(Uri))

编辑 2

根据用户 Anurag Singh 的要求，以下是清单和操作系统信息：

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

---

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.1"

    defaultConfig {
        applicationId "***"
        minSdkVersion 16
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        multiDexEnabled true
        vectorDrawables.useSupportLibrary = true
    }
}

---

编辑 3

这是 Postman 生成的代码，运行良好！

OkHttpClient client = new OkHttpClient();

MediaType mediaType = MediaType.parse("multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW");

RequestBody body = RequestBody.create(mediaType, "------WebKitFormBoundary7MA4YWxkTrZu0gW\r\nContent-Disposition: form-data; name=\"image\"; filename=\"sample 2.jpg\"\r\nContent-Type: image/jpeg\r\n\r\n\r\n------WebKitFormBoundary7MA4YWxkTrZu0gW\r\nContent-Disposition: form-data; name=\"upload_type\"\r\n\r\nprofile\r\n------WebKitFormBoundary7MA4YWxkTrZu0gW--");

Request request = new Request.Builder()
  .url("http://********/user/upload_image")
  .post(body)
  .addHeader("content-type", "multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW")
  .addHeader("authorization", "Bearer ******")
  .addHeader("cache-control", "no-cache")
  .addHeader("postman-token", "******")
  .build();

Response response = client.newCall(request).execute();

Answer 1

尝试在AndroidManifest.xml中添加以下权限

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>.

从 Android 6.0（API 级别 23）开始，用户在应用运行时授予应用权限，而不是在安装应用时。 Requesting Permissions at Run Time