Question

I’m having this code to post data to server by android application.
So , suppose before posting the data to server , the connection has lost (out of wifi or 3g)
or during post the connection lost.
How can I ensure the data has been post to server?
I implement a response from server side as a feedback message or as response, but do you think that is enough ?

Another scenario ( in critical system like a bank )

Suppose I send the data and it has posted well (e.g inserted to database ) but the error occur during getting the response !
Logically , because the response didn’t received , i will inform the user for example that the process didn’t posted and has to post it again! This is a problem !!

So what is the best way to implement or gain this level of insurance ?

try {
            // defaultHttpClient
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(http://www.exampleof.the/page_that_wil_receive_the_data.php?data=example);

            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();
            is = httpEntity.getContent();           

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        //"ISO-8859-1,utf-8;q=0.7,*;q=0.7"
        //"iso-8859-1"
        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is, "utf-8"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
            is.close();
            json = sb.toString();
        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }

        // try parse the string to a JSON object
        try {
            jObj = new JSONObject(json);
        } catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
        }

        // return JSON String
        return jObj;

    }

Answer 1

I believe for both the questions, HTTP 200 response code ensures that your requests are been posted successfully in the server.