Issue while posting data or pic to server

Question

I am facing issue while posting image in server. I am using httpConnection, and am getting issues such as Connection closed, Not Connected, TCP Timeout, Null Exception. Wwhile posting, I am posting a JSON Object,These issues occurs inconsistently, but happens randomly, I am not able to understand rootcause of issue?

byte[] buffer = new byte[20000];
            int bytesRead = responseData.read(buffer);
            while (bytesRead > 0) {
                byteArray.write(buffer, 0, bytesRead);
                bytesRead = responseData.read(buffer);
            }
            byteArray.close();

ow i replaced to

        byte[] byteArray = IOUtilities.streamToBytes(request.openInputStream()); 

I am trying to understand whether these change will be useful?

I am posting sample piece of Code for posting pic

request = (HttpConnection) connect.getConnection();
            request.setRequestMethod("POST");
            request.setRequestProperty("Content-Type", "application/json");
            os = request.openOutputStream();
            JSONObject jsonObjSMS;
            Vector dataValue = new Vector();//Vector for putting Images
            try {
                jsonObjSMS = new JSONObject();
                jsonObjSMS.put("strNo", MyObject.getNumber());
                byte[] encoded = Base64OutputStream.encode(dataValues, 0,dataValues.length,false, false);
                String baseEncodedStringArrayValue = new String(encoded, "UTF-8");
                dataValue.addElement(baseEncodedStringArrayValue);      
                jsonObjSMS.put("imageArray", dataValue);
            }catch(Exception e){
                System.out.println("Exception in JSON"+e);
            }
            os.write(jsonObjSMS.toString().getBytes("UTF-8"));  
            os.flush();
            byte[] byteArray = IOUtilities.streamToBytes(request.openInputStream());
            jsonResponse = new String(byteArray, "UTF-8");

Am I missing any piece of Code which is creating this error randomly?