Image upload failure over specific network from only android

Question

We are working on uploading image to our server from android device. Image is successfully uploading in server while using both mobile data and Wi-Fi, except one particular network which we are currently using. This new network setup don’t let pass any data from client end which has greater MTU size than 1460. So, all the packets from android device are rejected and cannot reach the server. Our iOS app can upload image to same server successfully with same network. We have found with tracing that iOS reduces the packet or chunk size if one packet is not successfully sent. But android devices are not behaving like that. We have also found that some social networking android apps can successfully upload image with our network. Some would probably say to change our network with correct settings, but we don’t want to do that as if we can have a defective network, some other people can also have that, where our android app will not work properly.

The works we have tried so far (all of which are working, except the new network) are given below: Main code which we were using from first:

private boolean uploadImage(String fileLoc, String title){
    try {
        String lineEnd = "\r\n";
        String twoHyphens = "--";
        String boundary = "*****";
        URL connectURL;

        connectURL = new URL(baseUrlString); // our server url to upload image

        FileInputStream fileInputStream = new FileInputStream(fileLoc);
            // ------------------ CLIENT REQUEST
            // Open a HTTP connection to the URL
            HttpURLConnection conn = (HttpURLConnection) connectURL
                    .openConnection();
            // Allow Inputs
            conn.setDoInput(true);
            // Allow Outputs
            conn.setDoOutput(true);
            // Don't use a cached copy.
            conn.setUseCaches(false);

            //conn.setChunkedStreamingMode(512);

            // Use a post method.
            conn.setRequestMethod("POST");
            conn.setRequestProperty("Connection", "Keep-Alive");
            conn.setRequestProperty("Content-Type",
                    "multipart/form-data;boundary=" + boundary);
            //conn.setFixedLengthStreamingMode(137931);             

            DataOutputStream dos = new DataOutputStream(
                    conn.getOutputStream());
            dos.writeBytes(twoHyphens + boundary + lineEnd);

            dos.writeBytes("Content-Disposition: form-data; name=\""
                    + param1 + "\"" + lineEnd
                    + lineEnd
                    + title
                    + lineEnd);
            dos.writeBytes(twoHyphens + boundary + lineEnd);


            dos.writeBytes("Content-Disposition: form-data; name=\"file\";filename=\""
                    + fileLoc
                    + "\""
                    + lineEnd);
            dos.writeBytes(lineEnd);

            // create a buffer of maximum size
            int bytesAvailable = fileInputStream.available();
            int maxBufferSize = 1024;
            int bufferSize = Math.min(bytesAvailable, maxBufferSize);
            byte[] buffer = new byte[bufferSize];

            // read file and write it into form...

            int 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
            fileInputStream.close();                
            dos.flush();
            InputStream is = conn.getInputStream();             
            // retrieve the response from server
            int ch;

            StringBuffer b = new StringBuffer();
            while ((ch = is.read()) != -1) {
                b.append((char) ch);
            }
            String response;
            response = b.toString().trim();
            dos.close();

            // here some work with response

            return sucs;


    } catch (Exception e) {
        e.printStackTrace();

    }
    return false;
}

Here we have also tried with

conn.setChunkedStreamingMode(512);

conn.setRequestProperty("Transfer-Encoding", "chunked");

to limit the chunk size, but it is ignored as the documentation says it is only a hint.

We have also tried with

conn.setFixedLengthStreamingMode(calculatedValueOfbytesForSameImage);

but failed.

Then we tried to implement other methods found in the web using Multipart and Socket:

All methods working except our network. Have also tried combining Multipart to ByteArrayOutputStream as https://stackoverflow.com/a/10225966/1246639. But still not working.

Is there any other method available to control the chunk size using other class like the InterfaceAddress or native support or if we are missing something in methods tried above? Thanks.....

Image upload failure over specific network from only android

0 Answers0