无法从android到ASP.NET服务器上传文件上传

Question

我已经坚持了一个星期了，我似乎无法到达任何地方。我试图通过ASP.NET将照片从myphone上传到API biult，但我一直收到错误：＆＃34; Error writing MIME multipart body part to output stream.＆＃34;。 这是我的java代码，我用来将照片上传为java.io.file对象：

urlConnection = (HttpURLConnection) this.url.openConnection();

urlConnection.setRequestProperty("Authorization","bearer " + User.GetToken());

String boundary = "----WebKitFormBoundary7MA4YWxkTrZu0gW";

urlConnection.setDoOutput(true);

urlConnection.setRequestProperty("Accept", "application/json");
urlConnection.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);

urlConnection.setRequestMethod("POST");

OutputStream outputStream = urlConnection.getOutputStream();
DataOutputStream dataOutputStream = new DataOutputStream(outputStream);

dataOutputStream.writeBytes("--" + boundary + "\r\n");
dataOutputStream.writeBytes("Content-Disposition: form-data; name=\"FormData\";
filename=\"filename.jpg\"; \r\nContent-Type: image/jpeg\r\n");
dataOutputStream.writeBytes("\r\n\r\n");

dataOutputStream.write(fileToByteArray(file)); // file = java.io.File

dataOutputStream.writeBytes("\r\n");
dataOutputStream.writeBytes("--" + boundary + "--\r\n\r\n");

dataOutputStream.flush();
dataOutputStream.close();

使用Postman时上传工作正常，所以我非常确定错误不在服务器端。