Ich versuche, Markierungen in Google Maps v2 aus meiner mySQL-Datenbank zu erstellen, aber das funktioniert nicht. Die Karte wird angezeigt, es sind jedoch keine Markierungen vorhanden. Kann mir jemand sagen, was falsch ist und was ich ändern muss? Ich habe auch versucht, getDouble getDouble (0) und getDouble (1) zu haben, aber ich habe irgendwo gelesen, um 0 und 2 zu versuchen. Es gibt auch eine Reihe von Importen aus mehreren Tutorials, die ich versucht habe. Ich werde später entfernen.

Meine Aktivität

import com.google.android.gms.common.ConnectionResult;

import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;

import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Dialog;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.widget.TextView;

import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;


public class ReadComments extends FragmentActivity {
    private static final String LOG_TAG = "JsOn ErRoR";

    private static final String SERVICE_URL = "my url";

    protected GoogleMap mapB;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.get_local);
        setUpMapIfNeeded();
    }

    @Override
    protected void onResume() {
        super.onResume();
        setUpMapIfNeeded();
    }

    private void setUpMapIfNeeded() {
        if (mapB == null) {
            mapB = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.mapB))
                    .getMap();
            if (mapB != null) {
                setUpMap();
            }
        }
    }

    private void setUpMap() {

        new Thread(new Runnable() {
            public void run() {
                try {
                    retrieveAndAddCities();
                } catch (IOException e) {
                    Log.e(LOG_TAG, "Cannot retrive cities", e);
                    return;
                }
            }
        }).start();
    }

    protected void retrieveAndAddCities() throws IOException {
        HttpURLConnection conn = null;
        final StringBuilder json = new StringBuilder();
        try {
            // Connect to the web service
            URL url = new URL(SERVICE_URL);
            conn = (HttpURLConnection) url.openConnection();
            InputStreamReader in = new InputStreamReader(conn.getInputStream());

            // Read the JSON data into the StringBuilder
            int read;
            char[] buff = new char[1024];
            while ((read = in.read(buff)) != -1) {
                json.append(buff, 0, read);
            }
        } catch (IOException e) {
            Log.e(LOG_TAG, "Error connecting to service", e);
            throw new IOException("Error connecting to service", e);
        } finally {
            if (conn != null) {
                conn.disconnect();
            }
        }

        // Must run this on the UI thread since it's a UI operation.
        runOnUiThread(new Runnable() {
            public void run() {
                try {
                    createMarkersFromJson(json.toString());
                } catch (JSONException e) {
                    Log.e(LOG_TAG, "Error processing JSON", e);
                }
            }
        });
    }

    void createMarkersFromJson(String json) throws JSONException {

        JSONArray jsonArray = new JSONArray(json);

        List<Marker> markers = new ArrayList<Marker>();

        for (int i = 0; i < jsonArray.length(); i++) {

            JSONObject jsonObj = jsonArray.getJSONObject(i);
            Marker marker = mapB.addMarker(new MarkerOptions()
                .title(jsonObj.getString("business_name"))
                .position(new LatLng(
                        jsonObj.getJSONArray("latlng").getDouble(0),
                        jsonObj.getJSONArray("latlng").getDouble(2)
                 ))
            );
            markers.add(marker);
        }
    }
}

meine JSON-Ausgabe von meiner URL

    [{"business_name":"Wine Bar","latlng":["43.6894658949280400","-116.3533687591552700"],
"business_id":"2","distance":"23.0298400562551"},
{"business_name":"Apple Headquarters","latlng":["37.3324083200000000","-122.0304781500000000"],
"business_id":"3","distance":"23.0298400562551"}]

Mein Logcat (Ich weiß nicht, wie ich den ganzen Logcat ziehen soll, aber das sind die Fehler)

08-21 00:00:27.371: E/JsOn ErRoR(357):  at com..ReadComments.createMarkersFromJson(ReadComments.java:127)
08-21 00:00:27.371: E/JsOn ErRoR(357):  at com..ReadComments$2.run(ReadComments.java:107)

Teilweise Screenshot