Question

my app records the gps location on a button click; however when I do it says I’m about three blocks away and is extremely inaccurate. Can you take a look at my code to see how I can improve it? Thanks

@Override
        protected Void doInBackground(Void... arg0) {
            SharedPreferences prefs = getSharedPreferences("Settings", 0);
            final String id = prefs.getString("ID", "");
            DefaultHttpClient httpclient = new DefaultHttpClient();
            HttpPost httpost = new HttpPost(
                    "http://iphone-radar.com/gps/gps_locations");

            JSONObject holder = new JSONObject();

            try {
                holder.put("id", id);
                LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
                Criteria criteria = new Criteria();
                String bestProvider = locationManager.getBestProvider(criteria,
                        false);
                LocationListener loc_listener=new LocationListener() {

                    @Override
                    public void onStatusChanged(String provider, int status, Bundle extras) {
                        // TODO Auto-generated method stub

                    }

                    @Override
                    public void onProviderEnabled(String provider) {
                        // TODO Auto-generated method stub

                    }

                    @Override
                    public void onProviderDisabled(String provider) {
                        // TODO Auto-generated method stub

                    }

                    @Override
                    public void onLocationChanged(Location location) {
                        // TODO Auto-generated method stub

                    }
                };
                try{
                    Looper.prepare();
                locationManager.requestLocationUpdates(bestProvider, 0, 0, loc_listener);
                }catch(Exception e){
                    e.printStackTrace();
                }
                Location location=locationManager.

getLastKnownLocation(bestProvider);
            Calendar c = Calendar.getInstance();
            SimpleDateFormat sdf = new SimpleDateFormat("hh:mmaa dd'/'MM'/'yyyy");

            holder.put("time", sdf.format(c.getTime()));
            holder.put("time_since_epoch", System.currentTimeMillis());
            try {
                holder.put("lat", location.getLatitude());
                holder.put("lon", location.getLongitude());
            } catch (NullPointerException e) {
                try {
                    holder.put("lat", -1.0);
                    holder.put("lon", -1.0);
                } catch (JSONException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }
            }

            StringEntity se = new StringEntity(holder.toString());
            httpost.setEntity(se);
            httpost.setHeader("Accept", "application/json");
            httpost.setHeader("Content-type", "application/json");

            ResponseHandler responseHandler = new BasicResponseHandler();
            String response = httpclient.execute(httpost, responseHandler);
            org.json.JSONObject obj;

                obj = new org.json.JSONObject(response);

        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

Answer 1

Yes there absolutely is, try adding some accuracy to your Criteria…

Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);

The default constructor for Criteria states (emphasis mine)

Constructs a new Criteria object. The new object will have no requirements on accuracy, power, or response time; will not require altitude, speed, or bearing; and will not allow monetary cost.