AsyncTask Null pointer exception. Google Places - android-asynctask

Question

i was developing app in android to get my nearby places and when i tried to run i made everything but got this exception and i do not know what is the reason to cause this exception. Please Helppp
LogCat
02-24 02:26:03.366: E/Trace(21173): error opening trace file: No such file or directory (2)
02-24 02:26:04.562: E/GooglePlayServicesUtil(21173): The Google Play services resources were not found. Check your project configuration to ensure that the resources are included.
02-24 02:26:11.773: E/AndroidRuntime(21173): FATAL EXCEPTION: main
02-24 02:26:11.773: E/AndroidRuntime(21173): java.lang.NullPointerException
02-24 02:26:11.773: E/AndroidRuntime(21173): at com.appscourt.maps.places.near.me.MainActivity$ParserTask.onPostExecute(MainActivity.java:270)
02-24 02:26:11.773: E/AndroidRuntime(21173): at com.appscourt.maps.places.near.me.MainActivity$ParserTask.onPostExecute(MainActivity.java:1)
02-24 02:26:11.773: E/AndroidRuntime(21173): at android.os.AsyncTask.finish(AsyncTask.java:631)
02-24 02:26:11.773: E/AndroidRuntime(21173): at android.os.AsyncTask.access$600(AsyncTask.java:177)
02-24 02:26:11.773: E/AndroidRuntime(21173): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
02-24 02:26:11.773: E/AndroidRuntime(21173): at android.os.Handler.dispatchMessage(Handler.java:99)
02-24 02:26:11.773: E/AndroidRuntime(21173): at android.os.Looper.loop(Looper.java:137)
02-24 02:26:11.773: E/AndroidRuntime(21173): at android.app.ActivityThread.main(ActivityThread.java:5059)
02-24 02:26:11.773: E/AndroidRuntime(21173): at java.lang.reflect.Method.invokeNative(Native Method)
02-24 02:26:11.773: E/AndroidRuntime(21173): at java.lang.reflect.Method.invoke(Method.java:511)
02-24 02:26:11.773: E/AndroidRuntime(21173): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:792)
02-24 02:26:11.773: E/AndroidRuntime(21173): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:555)
02-24 02:26:11.773: E/AndroidRuntime(21173): at dalvik.system.NativeStart.main(Native Method)
MainActivity
public class MainActivity extends FragmentActivity implements LocationListener {
GoogleMap googleMap;
Spinner placeTypeSpinner;
String[] placeType = null;
String[] placeTypeName = null;
double latitude = 0;
double longitude = 0;
Button btnFind;
HashMap<String, String> mMarkerPlaceLink = new HashMap<String, String>();
#SuppressLint("NewApi")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Array of places type
placeType = getResources().getStringArray(R.array.place_type);
//Array of places type name
placeTypeName = getResources().getStringArray(R.array.place_type_name);
// Creating an array adapter with an array of Place types
// to populate the spinner
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item, placeTypeName);
//Getting reference to the spinner
placeTypeSpinner = (Spinner)findViewById(R.id.spr_place_type);
//Setting adapter on spinner to set place types
placeTypeSpinner.setAdapter(adapter);
// Getting reference to Find Button
btnFind = ( Button ) findViewById(R.id.btnFind);
//Getting google play availability status
int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getBaseContext());
if(status != ConnectionResult.SUCCESS) {
int requestCode = 10;
Dialog dialog = GooglePlayServicesUtil.getErrorDialog(status, this, requestCode);
dialog.show();
} else { //Google Play Services are available
//Getting reference to the SupportMapFragment
googleMap = ((MapFragment) getFragmentManager().findFragmentById(R.id.map))
.getMap();
googleMap.setMyLocationEnabled(true);
LocationManager locMan = (LocationManager) getSystemService(LOCATION_SERVICE);
// Creating a criteria object to retrieve provider
Criteria criteria = new Criteria();
// Getting the name of the best provider
String provider = locMan.getBestProvider(criteria, true);
// Getting Current Location From GPS
Location location = locMan.getLastKnownLocation(provider);
if(location!=null){
onLocationChanged(location);
}
locMan.requestLocationUpdates(provider, 20000, 0, this);
googleMap.setOnInfoWindowClickListener(new OnInfoWindowClickListener() {
#Override
public void onInfoWindowClick(Marker marker) {
Intent intent = new Intent(getBaseContext(), PlaceDetailsActivity.class);
String reference = mMarkerPlaceLink.get(marker.getId());
intent.putExtra("reference", reference);
// Starting the Place Details Activity
startActivity(intent);
}
});
btnFind.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
int selectedPos = placeTypeSpinner.getSelectedItemPosition();
String type = placeType[selectedPos];
StringBuilder sb = new StringBuilder("https://maps.googleapis.com/maps/api/place/nearbysearch/json?");
sb.append("location=" + latitude + "," + longitude);
sb.append("&radius = 5000");
sb.append("&types = "+type);
sb.append("&sensor = true");
sb.append("&key = AIzaSyAbz9kNQKmgGRZJJj5fGcrp4DyfyvbxHm8");
// Creating a new non-ui thread task to download json data
PlacesTask placesTask = new PlacesTask();
// Invokes the "doInBackground()" method of the class PlaceTask
placesTask.execute(sb.toString());
}
});
}
//initializeMap();
}
/** A method to download json data from url */
String downloadUrl(String strUrl) throws IOException {
String data = "";
InputStream iStream = null;
HttpURLConnection urlConnection = null;
try{
URL url = new URL(strUrl);
// Creating an http connection to communicate with url
urlConnection = (HttpURLConnection) url.openConnection();
// Connecting to url
urlConnection.connect();
// Reading data from url
iStream = urlConnection.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(iStream));
StringBuffer sb = new StringBuffer();
String line = "";
while( ( line = br.readLine()) != null){
sb.append(line);
}
data = sb.toString();
br.close();
}catch(Exception e){
Log.d("Exception while downloading url", e.toString());
}finally{
iStream.close();
urlConnection.disconnect();
}
return data;
}
#Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
latitude = location.getLatitude();
longitude = location.getLongitude();
LatLng latLng = new LatLng(latitude, longitude);
googleMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
googleMap.animateCamera(CameraUpdateFactory.zoomTo(12));
}
#Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
public class PlacesTask extends AsyncTask<String, Integer, String>{
String data = null;
//MainActivity mainActivity = new MainActivity();
// Invoked by execute() method of this object
#Override
protected String doInBackground(String... url) {
try {
data = downloadUrl(url[0]);
}catch (Exception e) {
Log.d("Background Task", e.toString());
}
return data;
}
#Override
protected void onPostExecute(String result) {
ParserTask parserTask= new ParserTask();
// Start parsing the Google places in JSON format
// Invokes the "doInBackground()" method of the class ParseTask
parserTask.execute(result);
}
}
public class ParserTask extends AsyncTask<String, Integer, List<HashMap<String,String>>>{
JSONObject jObject;
//MainActivity mainActivity = new MainActivity();
//GoogleMap gMap;
//Invoked by execute() method of this object
#Override
protected List<HashMap<String, String>> doInBackground(String... jsonData) {
List<HashMap<String, String>> places = null;
PlaceJSONParser placeJsonParser = new PlaceJSONParser();
try{
jObject = new JSONObject(jsonData[0]);
/** Getting the parsed data as a List construct */
places = placeJsonParser.parse(jObject);
}catch(Exception e){
Log.d("Exception",e.toString());
}
return places;
}
#Override
protected void onPostExecute(List<HashMap<String, String>> list) {
//Clear all existing markers
//gMap = mainActivity.googleMap;
googleMap.clear();
super.onPostExecute(list);
for(int i = 0 ; i < list.size() ; i++) {
MarkerOptions markerOptions = new MarkerOptions();
// Getting a place from the places list
HashMap<String, String> hmPlace = list.get(i);
// Getting latitude of the place
double lat = Double.parseDouble(hmPlace.get("lat"));
// Getting longitude of the place
double lng = Double.parseDouble(hmPlace.get("lng"));
// Getting name
String name = hmPlace.get("place_name");
// Getting vicinity
String vicinity = hmPlace.get("vicinity");
LatLng latLng = new LatLng(lat, lng);
// Setting the position for the marker
markerOptions.position(latLng);
// Setting the title for the marker.
//This will be displayed on taping the marker
markerOptions.title(name + " : " + vicinity);
// Placing a marker on the touched position
googleMap.addMarker(markerOptions);
}
}
}
}

Answer 1

I think you are using Google's places api using HTTP GET. Like https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=-33.8670522,151.1957362&radius=500&types=food&name=harbour&sensor=false&key=Your_key.
While using GET method, be careful about the white spaces. Inside your code, there are spaces on both sides of " = ". So format your StringBuilder without spaces and try again.
StringBuilder sb = new StringBuilder("https://maps.googleapis.com/maps/api/place/nearbysearch/json?");
sb.append("location=" + latitude + "," + longitude);
sb.append("&radius=5000"); // take care of spaces here
sb.append("&types="+type); //
sb.append("&sensor=true"); //
sb.append("&key=Your_KEY"); //
After building your url, Log it and copy-paste it inside a web browser to check it.