java使用改型将文件作为multipart/formdata上传会产生400个错误代码

Question

尝试将图像作为多部分/表单数据上传，如下所示就是表单数据的形成

这就是spring boot方法的参数。此方法位于一个单独的spring boot应用程序中，该应用程序将文件保存到数据库中

public String uploadFile(@RequestParam("file") MultipartFile file,@RequestParam("desc") String desc,@RequestParam("uploadId") String uploadId ) {...}

我得到了错误代码400（错误请求），errorBody给出了空字符串。我无法理解我做错了什么。 下面的代码用于形成表单数据请求

try {
            RequestBody reqFile = RequestBody.create(MediaType.parse("image/jpeg"), file);
            MultipartBody.Part body = MultipartBody.Part.createFormData("file", file.getName(), reqFile);

            String descStr = file.getName();
            RequestBody desc = RequestBody.create(MediaType.parse("text/plain"), descStr);

            String uploadIdStr = receiptId;
            RequestBody uploadId = RequestBody.create(MediaType.parse("text/plain"), uploadIdStr);

            imgRequest = RetrofitHelper.uploadImage(ApplicationConstants.BEARER + " " + StringBox.getInstance(mActivity).getStringPreference(ApplicationConstants.ACCESS_TOKEN), body, desc, uploadId);
        } catch (IOException e) {
            Log.e(tag, e.getMessage());
        }


        imgRequest.enqueue(new Callback<ResponseBody>() {...}

改装API的配置如下所示

@Multipart
    @POST("/upload")
    Call<ResponseBody> uploadImage(@Header("Content-Type") String type,
                                   @Header("Authorization") String authorization,
                                   @Part MultipartBody.Part file,
                                   @Part("desc") RequestBody req,
                                   @Part("uploadId") RequestBody uploadId);

public static Call<ResponseBody> uploadImage(String accessToken, MultipartBody.Part body, RequestBody desc, RequestBody req) {
        RetrofitAPI mApi = RetrofitClient.getInstance().create(RetrofitAPI.class);

        Call<ResponseBody> uploadImage = mApi.uploadImage("multipart/form-data; boundary=" + System.currentTimeMillis(), accessToken, body, desc, req);

        return uploadImage;
    }

下面是响应标题

Date: Wed, 23 Sep 2020 07:13:25 GMT
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Pragma: no-cache
Expires: 0
X-Frame-Options: DENY
Transfer-Encoding: chunked
Connection: close

Answer 1

我在四处寻找我面临的一个相关问题，以下是我的发现。

---

1. 然后上传部分图片

   @Multipart
   @POST("api/uploadpic")
   fun submitDP(@Part body: MultipartBody.Part): Call<UploadImageResponse>
   

---

1. 避免手动添加标题，因为@Multipart注释会处理它。当我需要添加授权头时，我更喜欢拦截器

           class OAuthInterceptor(private val tokenType: String, private val 
            accessToken: 
            String) :
            Interceptor {
            override fun intercept(chain: Interceptor.Chain): okhttp3.Response {
            var request = chain.request()
            //do not pass content length to GET requests
            if(!request.method().equals("GET"))
            request = request.newBuilder()
           .header("Authorization", "$tokenType $accessToken")
           .header("Content-Length", request.body()?.contentLength().toString())
           .header("Host", "your.domain.com") //if this is not added then add 
            HostnameVerifier to interceptor
           .header("Accept", "application/json")
           .build()
       else
           request = request.newBuilder()
               .header("Authorization", "$tokenType $accessToken")
               .header("Host", "your.domain.com")
               .header("Accept", "application/json")
               .build()
       return chain.proceed(request)
   }
   

   }

---

1. 然后使用表单数据作为内容创建零件

   val requestFile: RequestBody = RequestBody.create(MediaType.parse("image/jpg"), 
   bytes)
   val body: MultipartBody.Part = MultipartBody.Part.createFormData("your_key", 
   "image", requestFile)