Question

我正在开发Android应用程序。我必须在服务器上传文件。如果我使用的文件大小小于4 MB，则上传成功。如果我使用的文件大小大于显示内存异常的文件大小。请帮我。我的代码如下。

HttpURLConnection conn = null;
    DataOutputStream dos = null;
    DataInputStream inStream = null;
    String existingFileName = Environment.getExternalStorageDirectory()
             + "/LoadImg/second.flv";;
    String lineEnd = "\r\n";
    String twoHyphens = "--";
    String boundary = "*****";
    int bytesRead, bytesAvailable, bufferSize;
    byte[] buffer;
    int maxBufferSize = 1*1024*1024;
    String responseFromServer = "";
    String urlString = "http://172.16.1.193/service.svc/UploadFile?filename=test.mp4";

    StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
            .permitAll().build();

    StrictMode.setThreadPolicy(policy);
    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(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(lineEnd);
        dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);

        // close streams
        Log.e("Debug", "File is written");
        fileInputStream.close();
        dos.flush();
        dos.close();

    } catch (MalformedURLException ex) {
        System.out.println("upload MalformedURLException >>>> "
                + ex.toString());
    } catch (IOException ioe) {
        System.out.println("upload IOException >>>> " + ioe.toString());
    }

    // ------------------ read the SERVER RESPONSE
    try {

        inStream = new DataInputStream(conn.getInputStream());
        String str;

        while ((str = inStream.readLine()) != null) {
            System.out.println("Server response >>>> " + str);
        }

        inStream.close();

    } catch (IOException ioex) {
        System.out.println("inStream exception >>>> "
                + ioex.getMessage().toString());
    }

Answer 1

你把你的下载视频代码放在了asynctask中吗？默认情况下，在Honeycomb中打开StrictMode。 Android Honeycomb: NetworkOnMainThreadException even when using AsyncTask and no strict mode?

Answer 2

看起来错误是由于您没有使用流模式并在将第一个字节发送到服务器之前完全读取文件而导致的。

您可以通过使用setChunkedStreamingMode（）API启用发送文件的流模式来解决此问题，下面是代码示例。

        // set the request mode as POST
        urlConnection.setRequestMethod("POST");

        // disable using cache.
        urlConnection.setUseCaches(false);

        // enable Output/Input.
        urlConnection.setDoOutput(true);
        urlConnection.setDoInput(true);

        // enable the streaming mode.
        urlConnection.setChunkedStreamingMode(128 * 1024);

        urlConnection.setRequestProperty("Connection", "Keep-Alive");
        urlConnection.setRequestProperty("Cache-Control", "no-cache");

在android中上传更大尺寸的文件时显示内存不足错误？

2 个答案: