I am trying to add markers from JSON Parsing. but the markers are not showing in the map. Can anyone please help me? Here is my code:
MainActivity.java
package com.hasibhasan.sampletask;
import java.util.ArrayList;
import org.json.JSONArray;
import org.json.JSONObject;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
public class MainActivity extends ActionBarActivity {
private GoogleMap googlemap;
private static String TAG_POSTS = "posts";
private static String TAG_DRIVER = "driver";
private static String TAG_ID = "id";
private static String TAG_LATITUDE = "lat";
private static String TAG_LONGITUDE = "lon";
private static String TAG_DATETIME = "recorded_datetime";
private static String TAG_USERID = "user_id";
private static String TAG_STATE = "cabby_state";
private static String TAG_VTYPE = "vehicleType";
private static String TAG_DRIVERNAME = "driver_name";
private static String TAG_PICNAME = "pic_name";
private static String TAG_RATING = "rating";
private static String TAG_CARMODEL = "car_model";
private static String TAG_NUMBERSIT = "number_sit";
private static String TAG_DISTANCE = "distance";
private static String TAG_OPERATOR = "operator";
private static String TAG_NEARESTDISTANCE = "nearest_distance";
private static String TAG_NDISTANCE = "distance";
private static String TAG_TIME = "time";
private static String TAG_CARMODELS = "car_models";
ArrayList<Taxi> taxi;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
taxi = new ArrayList<Taxi>();
new ParseJSONTask().execute();
googlemap = ((MapFragment) getFragmentManager().findFragmentById(
R.id.map)).getMap();
}
private class ParseJSONTask extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected Void doInBackground(Void... params) {
WebServiceHandler webServiceHandler = new WebServiceHandler();
String jsonstr = webServiceHandler
.getJSONData("http://54.186.247.213/unicabi/mobileservice/CurrentLocationService.php");
try {
JSONObject jsonObject = new JSONObject(jsonstr);
JSONArray postJson = jsonObject.getJSONArray(TAG_POSTS);
for (int i = 0; i < postJson.length(); i++) {
Taxi aTaxi = new Taxi();
JSONObject postObject = postJson.getJSONObject(i);
aTaxi.lat = postObject.getString(TAG_LATITUDE);
aTaxi.lon = postObject.getString(TAG_LONGITUDE);
aTaxi.driver_name = postObject.getString(TAG_DRIVERNAME);
taxi.add(aTaxi);
double lati = Double.parseDouble(aTaxi.lat);
double lon = Double.parseDouble(aTaxi.lon);
googlemap.addMarker(new MarkerOptions().title(
aTaxi.driver_name).position(new LatLng(lati, lon)));
}
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
}
}
}
Taxi. java (the model class)
package com.hasibhasan.sampletask;
public class Taxi {
public String posts = "";
public String success = "";
public String driver = "";
public String id = "";
public String lat = "";
public String lon = "";
public String recorded_datetime = "";
public String vehicleType = "";
public String driver_name = "";
public String pic_name = "";
public String rating = "";
public String car_model = "";
public String number_sit = "";
public String distance = "";
public String operator = "";
public String nearest_distance = "";
public String car_models = "";
}
Webservicehandler.java
package com.hasibhasan.sampletask;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
public class WebServiceHandler {
public WebServiceHandler() {
}
public String getJSONData(String url) {
String response = null;
DefaultHttpClient httpclient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
HttpEntity httpEntity = null;
HttpResponse httpResponse = null;
try {
httpResponse = httpclient.execute(httpGet);
httpEntity = httpResponse.getEntity();
response = EntityUtils.toString(httpEntity);
} catch (Exception e) {
e.printStackTrace();
}
return response;
}
}
Pass the array of MarkerOptions
to your onPostExecute
method which runs on the UI thread. You can add the markers to your map there. Example:
private class ParseJSONTask extends AsyncTask<Void, Void, List<MarkerOptions>> {
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected List<MarkerOptions> doInBackground(Void... params) {
WebServiceHandler webServiceHandler = new WebServiceHandler();
String jsonstr = webServiceHandler
.getJSONData("http://54.186.247.213/unicabi/mobileservice/CurrentLocationService.php");
try {
JSONObject jsonObject = new JSONObject(jsonstr);
JSONArray postJson = jsonObject.getJSONArray(TAG_POSTS);
List<MarkerOptions> markers = new ArrayList<MarkerOptions>();
for (int i = 0; i < postJson.length(); i++) {
Taxi aTaxi = new Taxi();
JSONObject postObject = postJson.getJSONObject(i);
aTaxi.lat = postObject.getString(TAG_LATITUDE);
aTaxi.lon = postObject.getString(TAG_LONGITUDE);
aTaxi.driver_name = postObject.getString(TAG_DRIVERNAME);
taxi.add(aTaxi);
double lati = Double.parseDouble(aTaxi.lat);
double lon = Double.parseDouble(aTaxi.lon);
markers.add(new MarkerOptions().title(aTaxi.driver_name).
position(new LatLng(lati, lon)));
return markers;
}
} catch (Exception e) {
e.printStackTrace();
}
return new ArrayList<MarkerOptions>();
}
@Override
protected void onPostExecute(List<MarkerOptions> markers) {
super.onPostExecute(markers);
for (MarkerOptions marker : markers) {
googlemap.addMarker(marker);
}
}
}
You are trying to update the UI from a non-UI thread. This not allowed and should normaly throw an exception. You should better use an custom listener to pass the taxi list to your UI thread from your onPostExecute
method. Make a custom Listener:
public interface ParsingFinishedListener{
public abstract void onParsingFinished(List<MarkerOptions> markers;
}
Add a constructor to your asyncTask like this:
public ParseJsonTask(ParsingFinishedListener l){
this.mParsingFinisedListener = l;
}
And in onPostExecute return the list:
@Override
protected void onPostExecute(List<MarkerOptions> markers) {
super.onPostExecute(markers);
mParsingFinishedListener.onParsingFinished(markers);
}
And rewrite your onCreate method:
@Override
public void onCreate(Bundele savedInstance){
super.onCreate(savedInstance);
setContentView(R.layout.activity_main);
googlemap = ((MapFragment) getFragmentManager().findFragmentById(
R.id.map)).getMap();
taxi = new ArrayList<Taxi>();
new ParseJSONTask().execute(new ParsingFinishedListener(){
@Override
public void onParsingFinished(List<MarkerOptions> m){
for (MarkerOptions marker : markers) {
googlemap.addMarker(marker);
}
}
);
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