Upload large (mp3) file from android to node.js using POST

I want to upload an mp3 file from my application to a node.js . There are two parameters accepted by the node.js and those are email_address and the mp3 file.

Following is the code I used yet failed to achieve the required functionality.

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> 

FileInputStream fileInputStream = new FileInputStream(sourceFile);
                 URL url = new URL(SERVER_PATH);

             // Open a HTTP  connection to  the URL
             conn = (HttpURLConnection) url.openConnection(); 
             conn.setUseCaches(false); // Don't use a Cached Copy
             conn.setConnectTimeout(30000);
             conn.setDoInput(true); // Allow Inputs
             conn.setDoOutput(true); // Allow Outputs

             conn.setRequestMethod("POST");
             conn.setRequestProperty("Connection", "Keep-Alive");
             conn.setRequestProperty("ENCTYPE", "multipart/form-data");
             conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
             conn.setRequestProperty("user_file", fileName); 
             //conn.connect();                 

             dos = new DataOutputStream(conn.getOutputStream());

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

             dos.writeBytes("Content-Disposition: form-data; name=\"user_file\";filename=\"" + fileName +"\"" + 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);

             // Responses from the server (code and message)
             int serverResponseCode = conn.getResponseCode();
             String serverResponseMessage = conn.getResponseMessage();

             Log.i("uploadFile", "HTTP Response is : "
                     + serverResponseMessage + ": " + serverResponseCode);

             if(serverResponseCode == 200){

                 Toast.makeText(getApplicationContext() ,"File Upload Complete.", 
                         Toast.LENGTH_SHORT).show();

             }    

             //close the streams //
             fileInputStream.close();
             dos.flush();
             dos.close();

When I run this code I get an exception. The exception object thrown is also null. Hence as a beginner to android I cannot find the issue.