Google Maps Android API V2で現在地の緯度・経度・標高を表示

Google Maps Android API V2でLocationを使った場合、標高（Altitude)を取得しようとしても、0.0の値しか返ってこないことがあります。

こういう場合、標高をHttpリクエストを使って、GoogleのElevation APIから取得してみます。

現在位置の取得には、端末のＧＰＳ機能を使います。

Eclipseの新規プロジェクトを作成する場合、Google-play-service_libを使います。

Google-play-service_libの使い方やMapsのAPIキー取得についてはこのページ参照

現在位置の取得の場合、上のページと異なるコードは以下の２つ。

【activity_main.xml】

<span class="tag">&lt;RelativeLayout <span class="attr">xmlns:android=</span><span class="value">"http://schemas.android.com/apk/res/android"</span>
    <span class="attr">xmlns:tools=</span><span class="value">"http://schemas.android.com/tools"</span>
    <span class="attr">android:layout_width=</span><span class="value">"match_parent"</span>
    <span class="attr">android:layout_height=</span><span class="value">"match_parent"</span>
    <span class="attr">tools:context=</span><span class="value">".MainActivity"</span> &gt;</span>
 
    <span class="tag">&lt;TextView
        <span class="attr">android:id=</span><span class="value">"@+id/textview1"</span>
        <span class="attr">android:layout_width=</span><span class="value">"wrap_content"</span>
        <span class="attr">android:layout_height=</span><span class="value">"wrap_content"</span> /&gt;</span>
 
    <span class="tag">&lt;fragment <span class="attr">xmlns:android=</span><span class="value">"http://schemas.android.com/apk/res/android"</span>
        <span class="attr">android:id=</span><span class="value">"@+id/map"</span>
        <span class="attr">android:layout_width=</span><span class="value">"match_parent"</span>
        <span class="attr">android:layout_height=</span><span class="value">"match_parent"</span>
        <span class="attr">android:layout_below=</span><span class="value">"@id/textview1"</span>
        <span class="attr">class=</span><span class="value">"com.google.android.gms.maps.SupportMapFragment"</span> /&gt;</span>
 
<span class="tag">&lt;/RelativeLayout&gt;</span>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

tools:context=".MainActivity" >

<TextView

android:id="@+id/textview1"

android:layout_width="wrap_content"

android:layout_height="wrap_content" />

<fragment xmlns:android="http://schemas.android.com/apk/res/android"

android:id="@+id/map"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:layout_below="@id/textview1"

class="com.google.android.gms.maps.SupportMapFragment" />

</RelativeLayout>

【MainActivity.java】

<span class="keyword">import</span> android.location.Criteria;
<span class="keyword">import</span> android.location.Location;

<span class="keyword">import</span> android.location.LocationManager;
<span class="keyword">import</span> android.os.Bundle;
<span class="keyword">import</span> android.support.v4.app.FragmentActivity;
<span class="keyword">import</span> android.view.Menu;
<span class="keyword">import</span> android.widget.TextView;
 
<span class="keyword">import</span> com.google.android.gms.maps.CameraUpdateFactory;
<span class="keyword">import</span> com.google.android.gms.maps.GoogleMap;
<span class="keyword">import</span> com.google.android.gms.maps.SupportMapFragment;
<span class="keyword">import</span> com.google.android.gms.maps.model.LatLng;

<span class="keyword">import</span> com.google.android.gms.common.GooglePlayServicesUtil;
<span class="keyword">import</span> com.google.android.gms.common.ConnectionResult;
<span class="keyword">import</span> android.app.Dialog;

<span class="keyword">import</span> android.util.Log;

<span class="keyword">import</span> com.google.android.gms.common.ConnectionResult;
<span class="keyword">import</span> com.google.android.gms.common.GooglePlayServicesClient.ConnectionCallbacks;
<span class="keyword">import</span> com.google.android.gms.common.GooglePlayServicesClient.OnConnectionFailedListener;
<span class="keyword">import</span> com.google.android.gms.location.LocationClient;
<span class="keyword">import</span> com.google.android.gms.location.LocationListener;
<span class="keyword">import</span> com.google.android.gms.location.LocationRequest;
<span class="keyword">import</span> com.google.android.gms.maps.model.CameraPosition;


<span class="keyword">public</span> <span class="keyword">class</span> MainActivity <span class="keyword">extends</span> FragmentActivity <span class="keyword">implements</span> OnConnectionFailedListener, LocationListener, ConnectionCallbacks {

    GoogleMap googleMap;
    
    HttpResponse httpResponse;
    
    <span class="keyword">public</span> <span class="keyword">double</span> latitude = <span class="num">0</span>;
    <span class="keyword">public</span> <span class="keyword">double</span> longitude = <span class="num">0</span>;
    
     <span class="keyword">private</span> LocationClient mLocationClient = null;
     <span class="keyword">private</span> <span class="keyword">static</span> <span class="keyword">final</span> LocationRequest REQUEST = LocationRequest.create()
            .setInterval(<span class="num">5000</span>) <span class="rem">// 5 seconds</span>
            .setFastestInterval(<span class="num">16</span>) <span class="rem">// 16ms = 60fps</span>
            .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    
    
    
    LocationManager locationManager;
        String provider;
        Location location;
        SupportMapFragment mapfragment;
    
    @Override
    <span class="keyword">public</span> <span class="keyword">void</span> onCreate(Bundle savedInstanceState) {
        <span class="keyword">super</span>.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        <span class="rem">//Google Play Servicesが使えるかどうかのステータス</span>
        <span class="keyword">int</span> status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getBaseContext());
 
        <span class="keyword">if</span>(status!=ConnectionResult.SUCCESS){ 
            <span class="rem">// Google Play Services が使えない場合</span>
            <span class="keyword">int</span> requestCode = <span class="num">10</span>;
            Dialog dialog = GooglePlayServicesUtil.getErrorDialog(status, <span class="keyword">this</span>, requestCode);
            dialog.show();
 
        }<span class="keyword">else</span> { 
            <span class="rem">// Google Play Services が使える場合</span>
            <span class="rem">//activity_main.xmlのSupportMapFragmentへの参照を取得</span>
            SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
            
            <span class="rem">//fragmentからGoogleMap objectを取得</span>
            googleMap = fm.getMap();
            
            <span class="rem">//Google MapのMyLocationレイヤーを使用可能にする</span>
            googleMap.setMyLocationEnabled(true);
            
            <span class="rem">//システムサービスのLOCATION_SERVICEからLocationManager objectを取得</span>
        locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
        mLocationClient = <span class="keyword">new</span> LocationClient(getApplicationContext(), <span class="keyword">this</span>, <span class="keyword">this</span>); <span class="rem">// ConnectionCallbacks, OnConnectionFailedListener</span>
        <span class="keyword">if</span> (mLocationClient != null) {
            <span class="rem">// Google Play Servicesに接続</span>
            mLocationClient.connect();
        }
    
        
        
    }
    
    @Override
    <span class="keyword">public</span> <span class="keyword">void</span> onPause(){
        <span class="keyword">super</span>.onPause();
        
        <span class="keyword">if</span> (mLocationClient != null) {
            <span class="rem">// Google Play Servicesに接続</span>
            mLocationClient.disconnect();
        }
        
    }


    @Override
    <span class="keyword">public</span> <span class="keyword">void</span> onLocationChanged(Location location) {

    <span class="rem">// 現在地に移動</span>
        CameraPosition cameraPos = <span class="keyword">new</span> CameraPosition.Builder()
            .target(<span class="keyword">new</span> LatLng(location.getLatitude(), location.getLongitude())).zoom(<span class="num">17.0</span>f)
            .bearing(<span class="num">0</span>).build();
        gMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPos)); 
    }
 
    @Override
    <span class="keyword">public</span> <span class="keyword">void</span> onConnectionFailed(ConnectionResult result) {
        <span class="rem">// TODO Auto-generated method stub</span>
    }

    @Override
    <span class="keyword">public</span> <span class="keyword">void</span> onConnected(Bundle connectionHint) {
        <span class="rem">// TODO Auto-generated method stub</span>
        mLocationClient.requestLocationUpdates(REQUEST,<span class="keyword">this</span>); <span class="rem">// LocationListener</span>
    }

    @Override
    <span class="keyword">public</span> <span class="keyword">void</span> onDisconnected() {
        <span class="rem">// TODO Auto-generated method stub</span>
    }
 
    @Override
    <span class="keyword">public</span> <span class="keyword">boolean</span> onCreateOptionsMenu(Menu menu) {
        <span class="rem">// Inflate the menu; this adds items to the action bar if it is present.</span>
        getMenuInflater().inflate(R.menu.main, menu);
        <span class="keyword">return</span> true;
    }
}

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import android.location.Criteria;

import android.location.Location;

import android.location.LocationManager;

import android.os.Bundle;

import android.support.v4.app.FragmentActivity;

import android.view.Menu;

import android.widget.TextView;

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.common.GooglePlayServicesUtil;

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

import android.app.Dialog;

import android.util.Log;

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

import com.google.android.gms.common.GooglePlayServicesClient.ConnectionCallbacks;

import com.google.android.gms.common.GooglePlayServicesClient.OnConnectionFailedListener;

import com.google.android.gms.location.LocationClient;

import com.google.android.gms.location.LocationListener;

import com.google.android.gms.location.LocationRequest;

import com.google.android.gms.maps.model.CameraPosition;

public class MainActivity extends FragmentActivity implements OnConnectionFailedListener, LocationListener, ConnectionCallbacks {

GoogleMap googleMap;

HttpResponse httpResponse;

public double latitude = 0;

public double longitude = 0;

private LocationClient mLocationClient = null;

private static final LocationRequest REQUEST = LocationRequest.create()

.setInterval(5000) // 5 seconds

.setFastestInterval(16) // 16ms = 60fps

.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

LocationManager locationManager;

String provider;

Location location;

SupportMapFragment mapfragment;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

//Google Play Servicesが使えるかどうかのステータス

int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getBaseContext());

if(status!=ConnectionResult.SUCCESS){

// Google Play Services が使えない場合

int requestCode = 10;

Dialog dialog = GooglePlayServicesUtil.getErrorDialog(status, this, requestCode);

dialog.show();

}else {

// Google Play Services が使える場合

//activity_main.xmlのSupportMapFragmentへの参照を取得

SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);

//fragmentからGoogleMap objectを取得

googleMap = fm.getMap();

//Google MapのMyLocationレイヤーを使用可能にする

googleMap.setMyLocationEnabled(true);

//システムサービスのLOCATION_SERVICEからLocationManager objectを取得

locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);

mLocationClient = new LocationClient(getApplicationContext(), this, this); // ConnectionCallbacks, OnConnectionFailedListener

if (mLocationClient != null) {

// Google Play Servicesに接続

mLocationClient.connect();

}

@Override

public void onPause(){

super.onPause();

if (mLocationClient != null) {

// Google Play Servicesに接続

mLocationClient.disconnect();

}

@Override

public void onLocationChanged(Location location) {

// 現在地に移動

CameraPosition cameraPos = new CameraPosition.Builder()

.target(new LatLng(location.getLatitude(), location.getLongitude())).zoom(17.0f)

.bearing(0).build();

gMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPos));

}

@Override

public void onConnectionFailed(ConnectionResult result) {

// TODO Auto-generated method stub

}

@Override

public void onConnected(Bundle connectionHint) {

// TODO Auto-generated method stub

mLocationClient.requestLocationUpdates(REQUEST,this); // LocationListener

}

@Override

public void onDisconnected() {

// TODO Auto-generated method stub

}

@Override

public boolean onCreateOptionsMenu(Menu menu) {

// Inflate the menu; this adds items to the action bar if it is present.

getMenuInflater().inflate(R.menu.main, menu);

return true;

}

標高を取得して、緯度・経度と一緒にTextViewに表示してみます。

AsyncTaskを使わない場合

<span class="keyword">private</span> <span class="keyword">void</span> getAltitude(<span class="keyword">double</span> lat,<span class="keyword">double</span> lon){
        
        HttpClient httpClient = <span class="keyword">new</span> DefaultHttpClient();
        <span class="rem">//Google Elevation APIサービスにアクセスして標高取得</span>
    <span class="rem">//ここではJSONではなくXMLで結果を返すようにしています</span>
        String uri = <span class="str">"http://maps.googleapis.com/maps/api/elevation/xml?locations="</span> + lat + <span class="str">","</span> + lon + <span class="str">"&amp;sensor=true"</span>;
        HttpGet request = <span class="keyword">new</span> HttpGet(uri);
        
        
        <span class="keyword">try</span> {
            httpResponse = httpClient.execute(request);
        } <span class="keyword">catch</span> (Exception e) {
            Log.e(<span class="str">"HttpSampleActivity"</span>, <span class="str">"Execute エラー"</span>);
        }
        
        <span class="keyword">int</span> status = httpResponse.getStatusLine().getStatusCode();
         
        <span class="keyword">if</span> (HttpStatus.SC_OK == status) {
            <span class="keyword">try</span> {
                ByteArrayOutputStream outputStream = <span class="keyword">new</span> ByteArrayOutputStream();
                httpResponse.getEntity().writeTo(outputStream);
        <span class="rem">//パーサーに渡す</span>
                xml_parse(outputStream.toString());
            } <span class="keyword">catch</span> (Exception e) {
                Log.e(<span class="str">"HttpSampleActivity"</span>, <span class="str">"エラー"</span>);
            }
        } <span class="keyword">else</span> {
            Log.e(<span class="str">"HttpSampleActivity"</span>, <span class="str">"Status"</span> + status);
        }
    }
    
    <span class="rem">//XMLパーサーで解析して標高値を取り出す</span>
    <span class="keyword">private</span> <span class="keyword">void</span> xml_parse(String str) {
        <span class="keyword">try</span>{
            XmlPullParser xmlPullParser = Xml.newPullParser();
            xmlPullParser.setInput(<span class="keyword">new</span> StringReader(str));
     
            <span class="keyword">int</span> eventType;
            <span class="keyword">while</span> ((eventType = xmlPullParser.next()) != XmlPullParser.END_DOCUMENT) {
                <span class="keyword">if</span> (eventType == XmlPullParser.START_TAG &amp;&amp; <span class="str">"elevation"</span>.equals(xmlPullParser.getName())) {
                    <span class="rem">//Log.d("HttpSampleActivity", xmlPullParser.nextText());</span>
                    String ALT = xmlPullParser.nextText();
            <span class="rem">//標高値の桁数調整</span>
                <span class="keyword">double</span> temp = Double.parseDouble(ALT);
                temp = temp * <span class="num">100</span>;
                temp = Math.ceil(temp);
                temp = temp / <span class="num">100</span>;
                ALT = String.valueOf(temp);
                    
                    <span class="rem">//</span>
                    TextView textview = (TextView) findViewById(R.id.textview1);
                    textview.setText(<span class="str">"標高:約"</span> + ALT + <span class="str">"(m),緯度:"</span> + latitude + <span class="str">",経度:"</span> + longitude);
                    
                }
            }
        } <span class="keyword">catch</span> (Exception e){
            Log.d(<span class="str">"HttpSampleActivity"</span>, <span class="str">"Error:parse"</span>);
        }
    }

private void getAltitude(double lat,double lon){

HttpClient httpClient = new DefaultHttpClient();

//Google Elevation APIサービスにアクセスして標高取得

//ここではJSONではなくXMLで結果を返すようにしています

String uri = "http://maps.googleapis.com/maps/api/elevation/xml?locations=" + lat + "," + lon + "&sensor=true";

HttpGet request = new HttpGet(uri);

try {

httpResponse = httpClient.execute(request);

} catch (Exception e) {

Log.e("HttpSampleActivity", "Execute エラー");

}

int status = httpResponse.getStatusLine().getStatusCode();

if (HttpStatus.SC_OK == status) {

try {

ByteArrayOutputStream outputStream = new ByteArrayOutputStream();

httpResponse.getEntity().writeTo(outputStream);

//パーサーに渡す

xml_parse(outputStream.toString());

} catch (Exception e) {

Log.e("HttpSampleActivity", "エラー");

}

} else {

Log.e("HttpSampleActivity", "Status" + status);

}

//XMLパーサーで解析して標高値を取り出す

private void xml_parse(String str) {

try{

XmlPullParser xmlPullParser = Xml.newPullParser();

xmlPullParser.setInput(new StringReader(str));

int eventType;

while ((eventType = xmlPullParser.next()) != XmlPullParser.END_DOCUMENT) {

if (eventType == XmlPullParser.START_TAG && "elevation".equals(xmlPullParser.getName())) {

//Log.d("HttpSampleActivity", xmlPullParser.nextText());

String ALT = xmlPullParser.nextText();

//標高値の桁数調整

double temp = Double.parseDouble(ALT);

temp = temp * 100;

temp = Math.ceil(temp);

temp = temp / 100;

ALT = String.valueOf(temp);

//

TextView textview = (TextView) findViewById(R.id.textview1);

textview.setText("標高:約" + ALT + "(m),緯度:" + latitude + ",経度:" + longitude);

}

} catch (Exception e){

Log.d("HttpSampleActivity", "Error:parse");

}

こんな感じ。表示対象は画像中央の青い点のところ。

インストール

インストール・実行は自己責任でお願いします。

Target：Android 2.3.3 or later

動作確認実機：Xperia acro(docomo) Android 2.3.4

AsyncTaskを使っていないので、Android 3.0以上では使えません…..の筈です。

アプリをＱＲコードからインストールする方法はコチラを参照

FRONT

地図と画像のサイト

Google Maps Android API V2で現在地の緯度・経度・標高を表示

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