我想在我的应用程序中实现一个谷歌地图，我正在尝试将字符串转换为lat和long，类似于“USA New York”-

package com.currencymeeting.activities;

import java.io.IOException;
import java.util.List;

import android.location.Address;
import android.location.Geocoder;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.widget.Toast;

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.MarkerOptions;

 public class GoogleMapsActivity extends FragmentActivity{

GoogleMap googleMap;
MarkerOptions markerOptions;
LatLng latLng;

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

    SupportMapFragment supportMapFragment = (SupportMapFragment)
            getSupportFragmentManager().findFragmentById(R.id.googleMap);

    googleMap = supportMapFragment.getMap();

    new GeocoderTask().execute("USA New York");

}

private class GeocoderTask extends AsyncTask<String, Void, List<Address>>{

    @Override
    protected List<Address> doInBackground(String... locationName) {
        // Creating an instance of Geocoder class
        Geocoder geocoder = new Geocoder(getBaseContext());
        List<Address> addresses = null;

        try {
            // Getting a maximum of 3 Address that matches the input text
            addresses = geocoder.getFromLocationName(locationName[0], 1);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return addresses;
    }

    @Override
    protected void onPostExecute(List<Address> addresses) {

        if(addresses==null || addresses.size()==0){
            Toast.makeText(getBaseContext(), "No Location found", Toast.LENGTH_SHORT).show();
        }

        // Clears all the existing markers on the map
        googleMap.clear();

        // Adding Markers on Google Map for each matching address
        for(int i=0;i<addresses.size();i++){

            Address address = (Address) addresses.get(i);

            // Creating an instance of GeoPoint, to display in Google Map
            latLng = new LatLng(address.getLatitude(), address.getLongitude());

            String addressText = String.format("%s, %s",
            address.getMaxAddressLineIndex() > 0 ? address.getAddressLine(0) : "",
            address.getCountryName());

            markerOptions = new MarkerOptions();
            markerOptions.position(latLng);
            markerOptions.title(addressText);

            googleMap.addMarker(markerOptions);

            // Locate the first location
            if(i==0)
                googleMap.animateCamera(CameraUpdateFactory.newLatLngZoom(latLng,16));
        }
    }
}

}