windy sinaga windy sinaga - 4 months ago 35
Android Question

java.lang.NullPointerException GoogleMaps V2

i just learning about android programming to show map.
but when i run this code ,there's some error. Can anybody explain why this error occurs? And what I can do to fix this problem? thank you very much.

Stacktrace:

12-01 02:58:27.324: E/AndroidRuntime(1360): FATAL EXCEPTION: main
12-01 02:58:27.324: E/AndroidRuntime(1360): java.lang.NullPointerException
12-01 02:58:27.324: E/AndroidRuntime(1360): at android.app.Instrumentation.execStartActivity(Instrumentation.java:1417)
12-01 02:58:27.324: E/AndroidRuntime(1360): at android.app.Activity.startActivityForResult(Activity.java:3390)
12-01 02:58:27.324: E/AndroidRuntime(1360): at android.app.Activity.startActivityForResult(Activity.java:3351)
12-01 02:58:27.324: E/AndroidRuntime(1360): at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:839)
12-01 02:58:27.324: E/AndroidRuntime(1360): at android.app.Activity.startActivity(Activity.java:3587)
12-01 02:58:27.324: E/AndroidRuntime(1360): at android.app.Activity.startActivity(Activity.java:3555)
12-01 02:58:27.324: E/AndroidRuntime(1360): at com.google.android.gms.dynamic.a$5.onClick(Unknown Source)
12-01 02:58:27.324: E/AndroidRuntime(1360): at android.view.View.performClick(View.java:4240)
12-01 02:58:27.324: E/AndroidRuntime(1360): at android.view.View$PerformClick.run(View.java:17721)
12-01 02:58:27.324: E/AndroidRuntime(1360): at android.os.Handler.handleCallback(Handler.java:730)
12-01 02:58:27.324: E/AndroidRuntime(1360): at android.os.Handler.dispatchMessage(Handler.java:92)
12-01 02:58:27.324: E/AndroidRuntime(1360): at android.os.Looper.loop(Looper.java:137)
12-01 02:58:27.324: E/AndroidRuntime(1360): at android.app.ActivityThread.main(ActivityThread.java:5103)
12-01 02:58:27.324: E/AndroidRuntime(1360): at java.lang.reflect.Method.invokeNative(Native Method)
12-01 02:58:27.324: E/AndroidRuntime(1360): at java.lang.reflect.Method.invoke(Method.java:525)
12-01 02:58:27.324: E/AndroidRuntime(1360): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
12-01 02:58:27.324: E/AndroidRuntime(1360): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
12-01 02:58:27.324: E/AndroidRuntime(1360): at dalvik.system.NativeStart.main(Native Method)
12-01 02:58:29.088: I/Process(1360): Sending signal. PID: 1360 SIG: 9


MainActivity.java

package unai.skripsi.mymaps;

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.BitmapDescriptorFactory;
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 android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.Menu;

public class MainActivity extends FragmentActivity {

static final LatLng RAGUNAN = new LatLng(-6.3039, 106.8267);
static final LatLng TAMANMINI = new LatLng(-6.29436, 106.8859);
private GoogleMap map;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
map= ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
if (map!=null){
Marker ragunan = map.addMarker(new MarkerOptions().position(RAGUNAN)
.title("Ragunan"));
Marker tamanmini = map.addMarker(new MarkerOptions().position(TAMANMINI)
.title("Taman mini")
.snippet("Taman mini itu indah")
.icon(BitmapDescriptorFactory.fromResource(R.drawable.ic_launcher)));

map.moveCamera(CameraUpdateFactory.newLatLngZoom(RAGUNAN, 15));
map.animateCamera(CameraUpdateFactory.zoomTo(10), 2000, null);

}
}


@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;
}

}


Layout

<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" >

<fragment
android:id="@+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:name="com.google.android.gms.maps.SupportMapFragment" />

</RelativeLayout>


Manifest

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

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

<permission
android:name="unai.skripsi.mymaps.permission.MAPS_RECEIVE"
android:protectionLevel="signature" />

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

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="unai.skripsi.mymaps.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="unai.skripsi.mymaps.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.gms.version"
android:value="@integer/google_play_services_version" />
<meta-data
android:name="com.google.android.maps.v2.API_KEY"
android:value="My API KEY" />
</application>

</manifest>

Answer

In your xml file change this class="com.google.android.gms.maps.MapFragment" to android:name="com.google.android.gms.maps.SupportMapFragment"

Extend your activity to FragmentActivty and change

map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map))
        .getMap(); to   
map= ((SupportMapFragment) getSupportFragmentManager()
                    .findFragmentById(R.id.map)).getMap();

Also check

if (map== null) 
            {
          map= ((SupportMapFragment) getSupportFragmentManager()
                    .findFragmentById(R.id.map)).getMap();}

Hope this helps.

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