Belajar Android GoogleMaps V2 Mencari Alamat dengan Geocoder

Belajar Android GoogleMaps V2 kali ini akan membahas tentang cara mencari alamat dengan menggunakan Geocoder service. Kalau pada tutorial yang lalu kita mampu menampilkan Alamat dari suatu titik, Pada tutorial ini adalah kebalikannya. Mari kita mulai.

1. Buat Project dengan nama “LearnGeocoderMaspV2” dan packagenya dengan nama “com.batikmob.learngeocodermaspv2”
2. Seperti biasa yang pertama kalai kita sentuh adalah bagian layout, edit main_activity.xml lalu ketikan kode berikut

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/RelativeLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

     <EditText
         android:id="@+id/editTextPlace"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_alignParentLeft="true"
         android:layout_alignParentTop="true"
         android:layout_toLeftOf="@+id/buttonSearch"
         android:ems="10"
         android:gravity="top"
         android:hint="place name" >

	 </EditText>

	 <Button
	     android:id="@+id/buttonSearch"
	     android:layout_width="wrap_content"
	     android:layout_height="wrap_content"
	     android:layout_alignParentRight="true"
	     android:layout_alignParentTop="true"
	     android:gravity="top"
	     android:text="Search" />

	 <fragment
	     android:id="@+id/mapgeocode"
	     android:layout_width="match_parent"
	     android:layout_height="match_parent"
	     android:layout_below="@+id/buttonSearch"
	     class="com.google.android.gms.maps.SupportMapFragment" >
	    </fragment>

</RelativeLayout>

3. Buat Class baru dengan nama “GeocodeJSONParser.java” lalu ketikan kode berikut

package com.batikmob.learngeocodermaspv2;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

public class GeocodeJSONParser {

	public List<HashMap<String,String>> parse(JSONObject jObject){

		JSONArray jPlaces = null;
		try {
			jPlaces = jObject.getJSONArray("results");
		} catch (JSONException e) {
			e.printStackTrace();
		}

		return getPlaces(jPlaces);
	}

	private List<HashMap<String, String>> getPlaces(JSONArray jPlaces){
		int placesCount = jPlaces.length();
		List<HashMap<String, String>> placesList = new ArrayList<HashMap<String,String>>();
		HashMap<String, String> place = null;

		/** Taking each place, parses and adds to list object */
		for(int i=0; i<placesCount;i++){
			try {
				/** Call getPlace with place JSON object to parse the place */
				place = getPlace((JSONObject)jPlaces.get(i));
				placesList.add(place);

			} catch (JSONException e) {
				e.printStackTrace();
			}
		}

		return placesList;
	}

	private HashMap<String, String> getPlace(JSONObject jPlace){

		HashMap<String, String> place = new HashMap<String, String>();
		String formatted_address = "-NA-";
		String lat="";
		String lng="";

		try {
			// Extracting formatted address, if available
			if(!jPlace.isNull("formatted_address")){
				formatted_address = jPlace.getString("formatted_address");
			}

			lat = jPlace.getJSONObject("geometry").getJSONObject("location").getString("lat");
			lng = jPlace.getJSONObject("geometry").getJSONObject("location").getString("lng");

			place.put("formatted_address", formatted_address);
			place.put("lat", lat);
			place.put("lng", lng);

		} catch (JSONException e) {
			e.printStackTrace();
		}
		return place;
	}
}

4. Edit class MainActivity.java lalu ketikan kode berikut

package com.batikmob.learngeocodermaspv2;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.List;

import org.json.JSONObject;

import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
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 MainActivity extends FragmentActivity {

private Button btnSearch;
private GoogleMap mMap;
private EditText edtPlace;

private static final String TAG="MainActivity";
static final LatLng INDONESIA = new LatLng(-6.29436, 106.8859);

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

	btnSearch = (Button) findViewById(R.id.buttonSearch);
	SupportMapFragment mapFragment = (SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.mapgeocode);

	// Getting reference to the Google Map
	mMap = mapFragment.getMap();
	mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(INDONESIA,5));

	edtPlace = (EditText) findViewById(R.id.editTextPlace);

	// Setting click event listener for the find button
	btnSearch.setOnClickListener(new OnClickListener() {

		@Override
		public void onClick(View arg0) {
			// TODO Auto-generated method stub
			String place_name = edtPlace.getText().toString();
			if(place_name==null || place_name.equals("")){
				Toast.makeText(getBaseContext(), "No Place is entered", Toast.LENGTH_SHORT).show();
				return;
			}

			String url = "https://maps.googleapis.com/maps/api/geocode/json?";

			try {
				// encoding special characters like space in the user input place
				place_name = URLEncoder.encode(place_name, "utf-8");
			} catch (UnsupportedEncodingException e) {
				e.printStackTrace();
			}

			String address = "address=" + place_name;

			String sensor = "sensor=false";

			// url , from where the geocoding data is fetched
			url = url + address + "&" + sensor;
			Log.v(TAG+"onClick", "url is: "+url);
		//	String modifiedURL= url.toString().replace(" ", "%20");

			// Instantiating DownloadTask to get places from Google Geocoding service
			// in a non-ui thread
			DownloadTask downloadTask = new DownloadTask();

			// Start downloading the geocoding places
			downloadTask.execute(url);

		}
	});

}

private 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;

}

 /** A class, to download Places from Geocoding webservice */
private class DownloadTask extends AsyncTask<String, Integer, String>{

        String data = null;

        // 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;
        }

        // Executed after the complete execution of doInBackground() method
        @Override
        protected void onPostExecute(String result){

        		ParserTask parserTask = new ParserTask();
                parserTask.execute(result);
        }

}

class ParserTask extends AsyncTask<String, Integer, List<HashMap<String,String>>>{

	JSONObject jObject;

	@Override
	protected List<HashMap<String,String>> doInBackground(String... jsonData) {

		List<HashMap<String, String>> places = null;
		GeocodeJSONParser parser = new GeocodeJSONParser();

        try{
        	jObject = new JSONObject(jsonData[0]);

            /** Getting the parsed data as a an ArrayList */
            places = parser.parse(jObject);

        }catch(Exception e){
                Log.d("Exception",e.toString());
        }
        return places;
	}

	// Executed after the complete execution of doInBackground() method
	@Override
	protected void onPostExecute(List<HashMap<String,String>> list){

		// Clears all the existing markers
		mMap.clear();

		for(int i=0;i<list.size();i++){

			// Creating a marker
            MarkerOptions markerOptions = new MarkerOptions();
            HashMap<String, String> hmPlace = list.get(i);

            double lat = Double.parseDouble(hmPlace.get("lat"));
            double lng = Double.parseDouble(hmPlace.get("lng"));

            String name = hmPlace.get("formatted_address");
            LatLng latLng = new LatLng(lat, lng);
            markerOptions.position(latLng);
            markerOptions.title(name);

            mMap.addMarker(markerOptions);

            // Locate the first location
            if(i==0)    	mMap.animateCamera(CameraUpdateFactory.newLatLng(latLng));
        }
	}
}

}

5. Edit AndroidManifest.xml lalu ketikan kode berikut

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.batikmob.learngeocodermaspv2"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <permission
        android:name="com.batikmob.learngeocodermaspv2.permission.MAPS_RECEIVE"
        android:protectionLevel="signature" />

    <uses-feature
        android:glEsVersion="0x00020000"
        android:required="true" />

    <uses-permission android:name="com.batikmob.learngeocodermaspv2.permission.MAPS_RECEIVE" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.batikmob.learngeocodermaspv2.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
          <meta-data
            android:name="com.google.android.maps.v2.API_KEY"
            android:value="AIzaSyAOr7w4HA1_TGZEyM6MKQz56dB7tDwH08w" />

    </application>

</manifest>

6. Run Project, pada place name ketikan bandung

Demo Geocoder Android Googlemaps v2

Belajar Android memang menyenangkan yah 🙂

Semoga Bermanfaat
Salam Hangat

Agus Haryanto

Referens:

http://sunil-android.blogspot.com/2013/07/google-map-android-api-v2-with-location.html