Ruby on rails Rails-从POST请求/八位字节流读取文件

我在一个POST请求中发送了一张照片，内容类型为：来自android应用程序的binary/octect stream，我不知道如何在服务器端读取它。当前代码返回500错误：

  def send_photo_attachment
    @tempfile = Tempfile.new
    @tempfile.binmode
    @tempfile.write request.body.read
    @tempfile.rewind

    uploaded_file = ActionDispatch::Http::UploadedFile.new(
          tempfile: @tempfile,
          filename: "photo.jpg"
        )
    uploaded_file.content_type = "image/jpeg"
    @message_content = MessageContent.new
    @message_content.content = uploaded_file
    @message_content.mimetype = "image/jpeg"
    render :attachment_id
  end

任何帮助都将不胜感激