Develop Reference

Google android map app crashes while getting latitude and longitude from the database

I need to show a bus location on the map, I have latitude and longitude saved in my database. To retrieve the Latitude and Longitude i am using AsynTask. But i think there is some problem with my code, app crashes if call AsyncTask in onMapReady. I checked without calling AsyncTask giving manual latitude and longitude, it works fine. Please help me fix the issue.
This is my code:
#Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
GetLocation getLocation = new GetLocation(getApplicationContext());
getLocation.execute();
}
public class GetLocation extends AsyncTask<String,Void,String> {
Context context;
GetLocation(Context ctx){
context = ctx;
}
#Override
protected String doInBackground(String... params) {
return null;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected void onPostExecute(String s) {
String login_url = "https://www.mywebsite.com/android/getlonglatt.php";
try {
URL url = new URL(login_url);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
String line = "";
String result="";
while ((line = bufferedReader.readLine())!=null){
result += line;
}
JSONObject jsonObject = new JSONObject(result);
String latitudedb = (String) jsonObject.get("latitude");
String longitudedb = (String) jsonObject.get("longitude");
String busnum = (String) jsonObject.get("busnum");
Double newlatt = Double.valueOf(latitudedb);
Double newlong = Double.valueOf(longitudedb);
LatLng location = new LatLng(newlatt, newlong);
MarkerOptions options = new MarkerOptions().position(location).title(busnum);
mMap.addMarker(options);
mMap.moveCamera(CameraUpdateFactory.newLatLng(location));
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(location,19.2f));
bufferedReader.close();
httpURLConnection.disconnect();
} catch (JSONException e) {
e.printStackTrace();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
protected void onProgressUpdate(Void... values) {
}
}

How we can send latitude and longitude to MySQL using Android?

Currently I am working with a project to get current latitude and longitude, I got that. Now I want the latitude and longitude send to MySQL database using Android. HTTP part of this program is not working.
LocationManager locationManager;
String mprovider;
String lat="", lon="";
private String Tag="MainActivity";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button b1=(Button)findViewById(R.id.button);
b1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
postData(lat, lon);
}
});
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
mprovider = locationManager.getBestProvider(criteria, false);
if (mprovider != null && !mprovider.equals("")) {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return;
}
Location location = locationManager.getLastKnownLocation(mprovider);
locationManager.requestLocationUpdates(mprovider, 0, 0, this);
if (location != null) {
onLocationChanged(location);
} else
Toast.makeText(getBaseContext(), "No Location Provider Found Check Your Code", Toast.LENGTH_SHORT).show();
}
}
private void postData(String la, String lo) {
HttpClient httpclient = new DefaultHttpClient();
HttpPost htget = new HttpPost("http://192.168.1.2/yy.php/"+la+"/"+lo);
try {
// Execute HTTP Post Request
HttpResponse response = httpclient.execute(htget);
String resp = response.getStatusLine().toString();
Toast.makeText(this, resp, Toast.LENGTH_SHORT).show();
} catch (ClientProtocolException e) {
Toast.makeText(this, "Error", Toast.LENGTH_SHORT).show();
} catch (IOException e) {
Toast.makeText(this, "Error", Toast.LENGTH_SHORT).show();
}
}
#Override
public void onLocationChanged(Location location) {
lat = Double.toString(location.getLatitude());
lon = Double.toString(location.getLongitude());
TextView tv = (TextView) findViewById(R.id.textView2);
tv.setText("Your Location is:" + lat + "--" + lon);
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onProviderDisabled(String provider) {
}

you can send data form android to server over http. here is more details

Use mysql's spatial extensions.
For making tables and using it with Google Maps api refer this:
Using MySQL and PHP with Google Maps
Before you start, I have few questions:
Which version of gmaps API are you working with?
How are you parsing the map marker (lat. long.) data?
How are you triggering the save (lat long/ map marker data event).
Workable method: create a JSON parser for parsing the Marker data (which is the JSON Object here).
public class MarkerJSONParser {
/** gets a JSONObject and returns a list */
public List<HashMap<String,String>> parse(JSONObject jObject){
JSONArray jMarkers = null;
try {
/** gets all the elements in the 'markers' array */
jMarkers = jObject.getJSONArray("markers");
} catch (JSONException e) {
e.printStackTrace();
}
/** enjoining getMarkers with the array of json object
* here each JSON object is a marker
*/
return getMarkers(jMarkers);
}
private List<HashMap<String, String>> getMarkers(JSONArray jMarkers){
int markersCount = jMarkers.length();
List<HashMap<String, String>> markersList = new ArrayList<HashMap<String,String>>();
HashMap<String, String> marker = null;
/** Parsing and adding each marker to the list object */
for(int i=0; i<markersCount;i++){
try {
/** Call getMarker with marker JSON object to parse the marker */
marker = getMarker((JSONObject)jMarkers.get(i));
markersList.add(marker);
}catch (JSONException e){
e.printStackTrace();
}
}
return markersList;
}
/** Parsing the Marker JSON object */
private HashMap<String, String> getMarker(JSONObject jMarker){
HashMap<String, String> marker = new HashMap<String, String>();
String lat = "-NA-";
String lng ="-NA-";
try {
// Latitude extraction
if(!jMarker.isNull("lat")){
lat = jMarker.getString("lat");
}
// Longitude extraction
if(!jMarker.isNull("lng")){
lng = jMarker.getString("lng");
}
marker.put("lat", lat);
marker.put("lng", lng);
} catch (JSONException e) {
e.printStackTrace();
}
return marker;
}
}
Paste this in your MySQL's MainActivity.java:
// enjoining OnClick Event listener for the GoogleMap
mGoogleMap.setOnMapClickListener(new OnMapClickListener() {
#Override
public void onMapClick(LatLng latlng) {
addMarker(latlng);
sendToServer(latlng);
}
});
// enjoining location retrieval
new RetrieveTask().execute();
}
// Marking lat. long. on the GoogleMaps
private void addMarker(LatLng latlng) {
MarkerOptions markerOptions = new MarkerOptions();
markerOptions.position(latlng);
markerOptions.title(latlng.latitude + "," + latlng.longitude);
mGoogleMap.addMarker(markerOptions);
}
// Enjoining bg thread to save marker inMySQL server
private void sendToServer(LatLng latlng) {
new SaveTask().execute(latlng);
}
// bg thread to save the marker in MySQL server
private class SaveTask extends AsyncTask<LatLng, Void, Void> {
#Override
protected Void doInBackground(LatLng... params) {
String lat = Double.toString(params[0].latitude);
String lng = Double.toString(params[0].longitude);
String strUrl = "http://www.yourserverurllocation.com";
URL url = null;
try {
url = new URL(strUrl);
HttpURLConnection connection = (HttpURLConnection) url
.openConnection();
connection.setRequestMethod("POST");
connection.setDoOutput(true);
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(
connection.getOutputStream());
outputStreamWriter.write("lat=" + lat + "&lng="+lng);
outputStreamWriter.flush();
outputStreamWriter.close();
InputStream iStream = connection.getInputStream();
BufferedReader reader = new BufferedReader(new
InputStreamReader(iStream));
StringBuffer sb = new StringBuffer();
String line = "";
while( (line = reader.readLine()) != null){
sb.append(line);
}
reader.close();
iStream.close();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}

Return LatLng object from nested asynctask

I have spent days on this, but I can't find a solution to my problem:
I'm developing an app that retrieves a list of theaters showing some movie selected by the user, parsing an HTML page in an AsyncTask.
I want to visualize those theaters on a Map with markers, so I need coordinates: once the "GetCinemaList" AsyncTask is completed, I try to populate my markerList in onPostExecute.
I have an SQLite db in which I store [theater|city|lat|lng]. So I first look up in the db, if it is not found I want call another AsyncTask to retrieve coordinates from HTTP google geocoding ('cause device geocoder returns null, causing the app to crash)
The problem is I am not able to return the LatLng point to the first AsyncTask...
I have tried to use listeners and to override processFinish(LatLng p), but I can't assign the value to my variable cause, accessing it from inner class it should be final.
Any help/idea? Thanks!
Here my code (containing error) for the AsyncTasks , in my Activity.
private class GetCinemaList extends AsyncTask<URL, Void, List<String>> {
private Context mContext;
public GetCinemaList(Context c){
mContext = c;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected List<String> doInBackground(URL... urls) {
List<String> cinemas = new ArrayList<>();
Document docHTML = null;
try {
docHTML = QueryUtils.makeRequest(urls[0]);
cinemas = QueryUtils.extractCinemasFromHTML(mTitile, docHTML);
} catch (IOException e) {
Log.e("JSwa", "Problem making request for parsing HTML "+e);
}
return cinemas;
}
#Override
protected void onPostExecute(List<String> result) {
super.onPostExecute(result);
cinemaList = result;
LatLng point;
pointList = new ArrayList<>();
for (String elem : cinemaList) {
String name = elem.split("\t")[0];
String orari = elem.split("\t")[1];
Cursor cursor = queryDB(mCinemaDbR, city, name);
if (!cursor.moveToFirst()) {
// call geocoding service
new LatLongFromService(name.concat(" " + city), new AsyncResponse() {
#Override
public void processFinish(LatLng output) {
point = output;
}
}).execute();
Log.d("JSwa", "Inserting point "+point.toString());
// insert new value in the database
long id = addCimena(mCinemaDbW, name, city, String.valueOf(point.latitude), String.valueOf(point.longitude));
// insert new value in the list
MarkerOptions marker = new MarkerOptions().position(point).title(name).snippet(orari);
pointList.add(marker);
}
else{
double lat = Double.parseDouble(cursor.getString(cursor.getColumnIndex(CinemaEntry.COLUMN_LAT)));
double lng = Double.parseDouble(cursor.getString(cursor.getColumnIndex(CinemaEntry.COLUMN_LNG)));
MarkerOptions marker = new MarkerOptions().position(new LatLng(lat,lng)).title(name)
.snippet(orari);
pointList.add(marker);
}
cursor.close();
}
for (MarkerOptions marker : pointList){
m_map.addMarker(marker);
}
}
}
// Sometimes happens that device gives location = null
public class LatLongFromService extends AsyncTask<Void, Void, StringBuilder> {
String place;
public AsyncResponse delegate = null;
public LatLongFromService(String place, AsyncResponse resp) {
this.place = place;
delegate = resp;
}
#Override
protected StringBuilder doInBackground(Void... params) {
try {
HttpURLConnection conn = null;
StringBuilder jsonResults = new StringBuilder();
String googleMapUrl = "http://maps.googleapis.com/maps/api/geocode/json?address=" + this.place + "&sensor=false";
URL url = new URL(googleMapUrl);
conn = (HttpURLConnection) url.openConnection();
InputStreamReader in = new InputStreamReader(
conn.getInputStream());
int read;
char[] buff = new char[1024];
while ((read = in.read(buff)) != -1) {
jsonResults.append(buff, 0, read);
}
return jsonResults;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(StringBuilder result) {
super.onPostExecute(result);
try {
JSONObject jsonObj = new JSONObject(result.toString());
JSONArray resultJsonArray = jsonObj.getJSONArray("results");
JSONObject location = resultJsonArray
.getJSONObject(0).getJSONObject("geometry").getJSONObject("location");
String lat_helper = location.getString("lat");
double lat = Double.valueOf(lat_helper);
String lng_helper = location.getString("lng");
double lng = Double.valueOf(lng_helper);
delegate.processFinish(new LatLng(lat, lng));
} catch (JSONException e) {
e.printStackTrace();
}
}
}`

Android location listener does not work on some devices

I need to find user location in android. As I do not want to use GPS, I tried below code to find user location based on his/her Network, this works on some devices but not on all of them, what is the problem? is it becuase of Android version or something like hardware issues?
private double x, y;
private LocationManager lm;
lm = (LocationManager) getActivity().getSystemService(
Context.LOCATION_SERVICE);
lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0,
0, locationListenerNetwork);
LocationListener locationListenerNetwork = new LocationListener() {
public void onLocationChanged(Location location) {
x = location.getLatitude();
y = location.getLongitude();
lm.removeUpdates(this);
Geocoder gcd = new Geocoder(getActivity(), Locale.getDefault());
List<Address> addresses;
addresses = gcd.getFromLocation(x, y, 1);
city = addresses.get(0).getLocality();
}

Try this
give latitude and longitude in FetchLocationTask class
latitude = 27.003434;
longitude = 23.458569;
new FetchLocationTask(getActivity(), latitude, longitude).execute();
public class FetchLocationTask extends AsyncTask<Void, Void, Void> {
public Context context;
// private ProgressDialog mProgressDialog;
public String addressUrl;
public BufferedReader in;
public FetchLocationTask(Context context, double lat, double longi) {
this.context = context;
addressUrl = "http://maps.googleapis.com/maps/api/geocode/json?latlng=" + lat + "," + longi + "&sensor=true";
}
#Override
protected void onPreExecute() {
}
/**
* Call the webservice and parse the data from the service in
* background.
*/
#Override
protected Void doInBackground(Void... params) {
try {
HttpClient httpClient = new DefaultHttpClient();// Client
HttpGet getRequest = new HttpGet();
getRequest.setURI(new URI(addressUrl));
HttpResponse response = httpClient.execute(getRequest);
in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
StringBuffer sb = new StringBuffer("");
String line = "";
String NL = System.getProperty("line.separator");
while ((line = in.readLine()) != null) {
sb.append(line + NL);
}
in.close();
String page = sb.toString();
JSONObject jsonObject = new JSONObject(page);
if (jsonObject.has("results")) {
JSONArray jsonArray = (JSONArray) jsonObject.get("results");
if (jsonArray.length() > 0) {
jsonObject = (JSONObject) jsonArray.get(0);
if (jsonObject.has("formatted_address")) {
address = (String) jsonObject.get("formatted_address");
}
}
return null;
}
return null;
} catch (Exception e) {
e.printStackTrace();
} finally {
if (in != null) {
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return null;
}
/**
* onPostExecute method after called webService and Set the data into
* adapter after background task is complete.
*/
#Override
protected void onPostExecute(Void result) {
if (address != null && address.length() > 0) {
Log.i("map", "My:::" + address);
etx_address.setText(address.toString());
}
}
}

How can I get the nearest Place (Village Or Street name)

In my application, when the user insert data i want to capture the user's exact place. I've tried so many methods. But none of them shown the exact place. (I meant that they display the country and admin area details only. I used getLocality and getFeatureName. If no Locality or Featurename found at that latitude and longitude then it will return a null value). My code is
Geocoder coder=new Geocoder(MainActivity.mContext,Locale.getDefault());
try
{
List<Address> listaddress=coder.getFromLocation(lat, lon, 1);
Address obj=listaddress.get(0);
String add=obj.getAddressLine(0);
add = add+"\n"+obj.getLatitude();
add = add+","+obj.getLongitude();
add = add + "," + obj.getCountryName();
add = add + "," + obj.getAdminArea();
add = add + "\n" + obj.getPostalCode();//null
add = add + "," + obj.getSubAdminArea();
add = add +","+obj.getFeatureName();//null
add = add+ "," +obj.getPremises();//null
add = add + "\n" + obj.getLocality();//null
add = add + "," + obj.getSubThoroughfare();//null
add = add+ "," +obj.getSubLocality();//null
add = add+"\n"+obj.getThoroughfare();
Log.v("IGA", "Address" + add);
//Toast.makeText(this, "Address=>" + add,Toast.LENGTH_SHORT).show();
t.setText(" "+add);
}
So I don't know how to solve it. But I have an idea. I need to find the nearest place to my exact latitude and longitude value, so that i can use that place. But I don't know how to find the nearest place (Nearest place means Village or Street not any others).
Also, In Android phones one application "Places" is there. It shows the correct area about where exactly I'm. Is there any possibilities to use the application "Places" to find my exact or nearest area. (I need the closest village or street, not subAdminArea (state). If yes, please explain.
Can anyone help me please

Using google reverse geocoding api you could get your actual street address by giving latitude and lantitude values.
Get Lat & Lan through GPS Receiver in Android
Then call google reverse geocoding api top fecth the actual street address:
MapManager in = new MapManager(
"http://maps.google.com/maps/geo?output=xml&oe=utf-8&ll="
+ lattitude + "%2C"
+ lantitude + "&key=get-key-from-google-map-api");
content = in.URLRequest();
System.out.println("Addrss:"+in.parseMapData(content));
Class MapManager{
String url ="";
MapManager(String url){
this.url = url;
}
public String parseMapData(String data) {
String addr = "";
try {
InputStream in = new ByteArrayInputStream(data.getBytes());
DocumentBuilder builder = DocumentBuilderFactory.newInstance()
.newDocumentBuilder();
Document doc = builder.parse(in, null);
NodeList address = doc.getElementsByTagName("address");
addr = address.item(0).getTextContent();
} catch (Throwable t) {
Log.v("Exception", "Exception: " + t.toString());
}
return addr;
}
public String URLRequest() {
httpclient = new DefaultHttpClient();
try {
httpget = new HttpGet(url);
httpresponse = httpclient.execute(httpget);
httpentity = httpresponse.getEntity();
response = EntityUtils.toString(httpentity);
response = response.trim();
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
IsServerConn = false;
e.printStackTrace();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (Exception e) {
IsServerConn = false;
}
return response;
}
}

private class MatchingNearByLocationTask extends
AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
progressDialog = new ProgressDialog(getContext());
progressDialog.setMessage("Loading...");
progressDialog.setCancelable(true);
progressDialog.show();
}
#Override
protected Void doInBackground(Void... arg0) {
jsonStr = getLocationInfo(latitude, longitude).toString(); // put longitude and latitude value from which u want find nearer palce
if (jsonStr != null) {
Log.i("location--??", jsonStr);
JSONObject jsonObj;
try {
jsonObj = new JSONObject(jsonStr);
JSONObject responseJsonObject = jsonObj
.getJSONObject("response");
JSONArray venues = responseJsonObject
.getJSONArray(("venues"));
for (int index = 0; index < venues.length(); index++) {
locationObject = new NearByLocationObject();
String id = "", name = "", longitude = "", latitude = "";
JSONObject venuesJsonObj = venues.getJSONObject(index);
id = venuesJsonObj.getString("id");
name = venuesJsonObj.getString("name");
JSONObject latLngJsonObj = venuesJsonObj
.getJSONObject("location");
longitude = latLngJsonObj.getString("lng");
latitude = latLngJsonObj.getString("lat");
locationObject.setId(id);
locationObject.setNameOfLocation(name);
locationObject.setLocationOfLatitude(latitude);
locationObject.setLocationOfLongitude(longitude);
nearByLocationArrayList.add(locationObject);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (progressDialog.isShowing()) {
progressDialog.dismiss();
}
adapter = new NearByLocationArrayAdapter(getContext(),
R.layout.nearby_location_item, nearByLocationArrayList);
nearByLocationListView.setAdapter(adapter);
}
#Override
protected void onCancelled() {
super.onCancelled();
progressDialog.dismiss();
}
}
private JSONObject getLocationInfo(double lat, double lng) {
HttpGet httpGet = new HttpGet(
"https://api.foursquare.com/v2/venues/search?ll="
+ lat
+ ","
+ lng
+ "&radius=100&oauth_token=TNFKWLITLCJYWPSLAXQNHCSDPHZ4IS5PWVDD45OI224JGFFM&v=20140407&intent=checkin");
HttpClient client = new DefaultHttpClient();
HttpResponse response;
StringBuilder stringBuilder = new StringBuilder();
try {
response = client.execute(httpGet);
HttpEntity entity = response.getEntity();
InputStream stream = entity.getContent();
int b;
while ((b = stream.read()) != -1) {
stringBuilder.append((char) b);
}
} catch (ClientProtocolException e) {
} catch (IOException e) {
}
JSONObject jsonObject = new JSONObject();
try {
jsonObject = new JSONObject(stringBuilder.toString());
} catch (JSONException e) {
e.printStackTrace();
}
return jsonObject;
}
public class NearByLocationObject {
String id = "", nameOfLocation, locationOfLatitude, LocationOfLongitude;
public NearByLocationObject() {
super();
// TODO Auto-generated constructor stub
}
public NearByLocationObject(String id, String nameOfLocation,
String locationOfLatitude, String locationOfLongitude) {
super();
this.id = id;
this.nameOfLocation = nameOfLocation;
this.locationOfLatitude = locationOfLatitude;
LocationOfLongitude = locationOfLongitude;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getNameOfLocation() {
return nameOfLocation;
}
public void setNameOfLocation(String nameOfLocation) {
this.nameOfLocation = nameOfLocation;
}
public String getLocationOfLatitude() {
return locationOfLatitude;
}
public void setLocationOfLatitude(String locationOfLatitude) {
this.locationOfLatitude = locationOfLatitude;
}
public String getLocationOfLongitude() {
return LocationOfLongitude;
}
public void setLocationOfLongitude(String locationOfLongitude) {
LocationOfLongitude = locationOfLongitude;
}
}