Using HttpClient and HttpPost in Android with post parameters

Question

I'm writing code for an Android application that is supposed to take data, package it as Json and post it to a web server, that in turn is supposed to respond with json.

Using a GET request works fine, but for some reason using POST all data seems to get stripped and the server does not receive anything.

Here's a snippet of the code:

HttpParams params = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(params, 5000);
HttpConnectionParams.setSoTimeout(params, 5000);        
DefaultHttpClient httpClient = new DefaultHttpClient(params);
BasicCookieStore cookieStore = new BasicCookieStore();
httpClient.setCookieStore(cookieStore);

String uri = JSON_ADDRESS;
String result = "";
String username = "user";
String apikey = "something";
String contentType = "application/json";

JSONObject jsonObj = new JSONObject();

try {
    jsonObj.put("username", username);
    jsonObj.put("apikey", apikey);
} catch (JSONException e) {
    Log.e(TAG, "JSONException: " + e);
}

HttpPost httpPost = new HttpPost(uri);
List<NameValuePair> postParams = new ArrayList<NameValuePair>();
postParams.add(new BasicNameValuePair("json", jsonObj.toString()));
HttpGet httpGet = null;
try {
    UrlEncodedFormEntity entity = new UrlEncodedFormEntity(postParams);
    entity.setContentEncoding(HTTP.UTF_8);
    entity.setContentType("application/json");
    httpPost.setEntity(entity);

    httpPost.setHeader("Content-Type", contentType);
    httpPost.setHeader("Accept", contentType);
} catch (UnsupportedEncodingException e) {
    Log.e(TAG, "UnsupportedEncodingException: " + e);
}

try {
    HttpResponse httpResponse = httpClient.execute(httpPost);
    HttpEntity httpEntity = httpResponse.getEntity();

    if (httpEntity != null) {
        InputStream is = httpEntity.getContent();
        result = StringUtils.convertStreamToString(is);
        Log.i(TAG, "Result: " + result);
    }
} catch (ClientProtocolException e) {
    Log.e(TAG, "ClientProtocolException: " + e);
} catch (IOException e) {
    Log.e(TAG, "IOException: " + e);
}

return result;

I think I have followed the general guidelines on how to create the parameters and post them, but apparently not.

Any help or pointers to where I can find a solution, are very welcome at this point (after spending a few hours realizing no post data was ever sent). The real server is running Wicket on Tomcat, but I've also tested it out on a simple PHP page, with no difference.

Answer 1

You can actually send it as JSON the following way:

// Build the JSON object to pass parameters
JSONObject jsonObj = new JSONObject();
jsonObj.put("username", username);
jsonObj.put("apikey", apikey);
// Create the POST object and add the parameters
HttpPost httpPost = new HttpPost(url);
StringEntity entity = new StringEntity(jsonObj.toString(), HTTP.UTF_8);
entity.setContentType("application/json");
httpPost.setEntity(entity);
HttpClient client = new DefaultHttpClient();
HttpResponse response = client.execute(httpPost);

Answer 2

have you tried doing it without the JSON object and just passed two basicnamevaluepairs? also, it might have something to do with your serversettings

Update: this is a piece of code I use:

InputStream is = null;
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
    nameValuePairs.add(new BasicNameValuePair("lastupdate", lastupdate)); 

try {
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost(connection);
        httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
        HttpResponse response = httpclient.execute(httppost);
        HttpEntity entity = response.getEntity();
        is = entity.getContent();
        Log.d("HTTP", "HTTP: OK");
    } catch (Exception e) {
        Log.e("HTTP", "Error in http connection " + e.toString());
    }

Answer 3

public class GetUsers extends AsyncTask {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();

    }

    private String convertStreamToString(InputStream is) {
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        StringBuilder sb = new StringBuilder();

        String line = null;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        return sb.toString();
    }

    public String connect()
    {
        HttpClient httpclient = new DefaultHttpClient();

        // Prepare a request object
        HttpPost htopost = new HttpPost("URL");
        htopost.setHeader(new BasicHeader("Authorization","Basic Og=="));

        try {

            JSONObject param = new JSONObject();
            param.put("PageSize",100);
            param.put("Userid",userId);
            param.put("CurrentPage",1);

            htopost.setEntity(new StringEntity(param.toString()));

            // Execute the request
            HttpResponse response;

            response = httpclient.execute(htopost);
            // Examine the response status
            // Get hold of the response entity
            HttpEntity entity = response.getEntity();

            if (entity != null) {

                // A Simple JSON Response Read
                InputStream instream = entity.getContent();
                String result = convertStreamToString(instream);

                // A Simple JSONObject Creation
                json = new JSONArray(result);

                // Closing the input stream will trigger connection release
                instream.close();
                return ""+response.getStatusLine().getStatusCode();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

    @Override
    protected String doInBackground(String... urls) {
        return connect();
    }

    @Override
    protected void onPostExecute(String status){
        try {

            if(status.equals("200"))
            {

                    Global.defaultMoemntLsit.clear();

                    for (int i = 0; i < json.length(); i++) {
                        JSONObject ojb = json.getJSONObject(i);
                        UserMomentModel u = new UserMomentModel();
                        u.setId(ojb.getString("Name"));
                        u.setUserId(ojb.getString("ID"));


                        Global.defaultMoemntLsit.add(u);
                    }




                            userAdapter = new UserAdapter(getActivity(), Global.defaultMoemntLsit);
                            recycleView.setAdapter(userMomentAdapter);
                            recycleView.setLayoutManager(mLayoutManager);
           }



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

        }
    }
}

Answer 4

I've just checked and i have the same code as you and it works perferctly. The only difference is how i fill my List for the params :

I use a : ArrayList<BasicNameValuePair> params

and fill it this way :

 params.add(new BasicNameValuePair("apikey", apikey);

I do not use any JSONObject to send params to the webservices.

Are you obliged to use the JSONObject ?