Question

我正在尝试创建一个可以将Android应用程序连接到服务器的应用程序，我需要上传和下载2个或更多文件我找到了这段代码

private void doFileUpload() {
        HttpURLConnection conn = null;
        DataOutputStream dos = null;
        DataInputStream inStream = null;
        String existingFileName = Environment.getExternalStorageDirectory()
                .getAbsolutePath() + "/android/data/[package]/files/productHistory";
        **String existingFileName2 = Environment.getExternalStorageDirectory()
                .getAbsolutePath() + "/android/data/[package]/files/productStock";**
        String lineEnd = "\r\n";
        String twoHyphens = "--";
        String boundary = "*****";
        int bytesRead, bytesAvailable, bufferSize;
        byte[] buffer;
        int maxBufferSize = 1 * 1024 * 1024;
        String responseFromServer = "";
        String urlString = "http://192.168.1.112/johnson/learn/android/";
        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=\"uploadedfile\";filename=\""
                    + existingFileName + "\"" + lineEnd);
            **dos.writeBytes("Content-Disposition: form-data; name=\"uploadedfile\";filename=\""
                    + existingFileName2 + "\"" + lineEnd);**
            dos.writeBytes(lineEnd);
            // create a buffer of maximum size
            bytesAvailable = fileInputStream.available();
            bufferSize = Math.min(bytesAvailable, maxBufferSize);
            buffer = new byte[bufferSize];
            // read file and write it into form...
            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);
            }
            // send multipart form data necesssary after file data...
            dos.writeBytes(lineEnd);
            dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
            // close streams
            Log.e("Debug", "File is written");
            fileInputStream.close();
            dos.flush();
            dos.close();
        } catch (MalformedURLException ex) {
            Log.e("Debug", "error: " + ex.getMessage(), ex);
        } catch (IOException ioe) {
            Log.e("Debug", "error: " + ioe.getMessage(), ioe);
        }
        // ------------------ read the SERVER RESPONSE
        try {
            inStream = new DataInputStream(conn.getInputStream());
            String str;

            while ((str = inStream.readLine()) != null) {
                Log.e("Debug", "Server Response " + str);
            }
            inStream.close();

        } catch (IOException ioex) {
            Log.e("Debug", "error: " + ioex.getMessage(), ioex);
        }
    }

粗体文字由我编辑，但它失败了，它只上传第一个

我的问题是1.如何使用代码上传2个/更多文件？ 2.以及如何下载它们？

提前致谢

Answer 1

不确定您是否必须使用特定服务器，但Parse提供了一个带有直观API的甜蜜SDK，可以在服务器之间发送/接收数据（在您的情况下为图像）。如果您不想花费太多时间编写向服务器发送数据和从服务器接收数据的代码，我建议您尝试一下。（不，我不在Parse工作，只是他们工具的忠实粉丝：P）。

上传和下载2个或更多文件到/从服务器

1 个答案: