通过 Android - Node.js 进行分段请求

Question

我正在尝试将图像从安卓发送到节点服务器。我做了什么：

        try{
            //------------------ CLIENT REQUEST
            FileInputStream fileInputStream = new FileInputStream(new File(existingFileName) );
            // open a URL connection to the Servlet
            URL url = new URL(urlString);
            // Open a HTTP connection to the URL
            conn = (HttpURLConnection) url.openConnection();
            // Allow Inputs
            conn.setDoInput(true);
            // Allow Outputs
            conn.setDoOutput(true);
            // Don't use a cached copy.
            conn.setUseCaches(false);
            // Use a post method.
            conn.setRequestMethod("POST");
            conn.setRequestProperty("Connection", "Keep-Alive");
            conn.setRequestProperty("Content-Type", "multipart/form-data;boundary="+boundary);
            dos = new DataOutputStream( conn.getOutputStream() );
            dos.writeBytes(twoHyphens + boundary + lineEnd);
            dos.writeBytes("Content-Disposition: form-data; name="image_upload";originalFilename="" + params[1] + "";path="" + params[0] + """ + lineEnd); // originalFilename is the Name of the File to be uploaded
            dos.writeBytes(lineEnd);
            bytesAvailable = fileInputStream.available();
            bufferSize = Math.min(bytesAvailable, maxBufferSize);
            buffer = new byte[bufferSize];
            bytesRead = fileInputStream.read(buffer, 0, bufferSize);
            while (bytesRead > 0){
                dos.write(buffer, 0, bufferSize);
                bytesAvailable = fileInputStream.available();
                bufferSize = Math.min(bytesAvailable, maxBufferSize);
                bytesRead = fileInputStream.read(buffer, 0, bufferSize);
            }
            dos.writeBytes(lineEnd);
            dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
            fileInputStream.close();
            dos.flush();
            dos.close();
        }

我在节点中获取image_upload文件参数作为files.image_upload[0].originalFilename和files.image_upload[0].path

问题发生在image_upload[0]。服务器崩溃说 TypeError: Cannot read property '0' of undefined

Answer 1

为图像路径文件指定 mime 类型。

Answer 2

替换了一部分代码，它现在可以工作了。

        dos.writeBytes("Content-Disposition: form-data; name="image_upload"; filename=""+params[1]+"""+lineEnd);
        dos.writeBytes("Content-Type: "undefined""+lineEnd);
        dos.writeBytes(lineEnd);