Getting long and lat returns a nullpointexception in android map v2

Question

I tried following the tutorial from Google here. I believe I followed every instruction written but I still get nullpointexception when I try to get my long and lat coordinates.

It works fine if I press the target icon in the map that redirects me to my current location. But when I try it programmatically, it returns nullpointexception. I tried looking in stackoverflow for similar situations like mine but so far none of them works.

If you can provide me with a sample working source file or code that I can test myself it is much appreciated. Below are my source code in case I missed something. Thanks in advance.

manifest file

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

    <supports-screens
        android:largeScreens="true"
        android:normalScreens="true"
        android:smallScreens="false"
        android:xlargeScreens="true" />

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

    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <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" />

    <uses-feature
        android:name="android.hardware.camera"
        android:required="false" />

    <uses-sdk
        android:minSdkVersion="11"
        android:targetSdkVersion="19" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <uses-library android:name="com.google.android.maps" />

        <meta-data
            android:name="com.google.android.gms.version"
            android:value="@integer/google_play_services_version" />

        <activity
            android:name="sample.map.activity"
            android:configChanges="orientation"
            android:label="@string/app_name"
            android:screenOrientation="portrait" >
            <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="AIzaSyAdqod8BHch40COYn19c6Ds0uhyfkX25SA" />
    </application>

</manifest>

map activity class

import android.location.Criteria;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.model.LatLng;

public class MapActivity extends ActionBarActivity {
    GoogleMap map;
    Location location;
    LatLng myLocation;
    LocationManager lm;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_map);
        lm = (LocationManager) getSystemService(LOCATION_SERVICE);
        Criteria criteria = new Criteria();
        String provider = lm.getBestProvider(criteria, true);

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

        map.setMyLocationEnabled(true);
        location = lm.getLastKnownLocation(provider);
        double mLat = location.getLatitude();
        double mLong = location.getLongitude();
        Toast.makeText(getApplicationContext(), mLat+" "+mLong, Toast.LENGTH_LONG).show();

        map.animateCamera(CameraUpdateFactory.newLatLngZoom(myLocation, 13));

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.map, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

Here is the stack trace

05-18 22:45:44.043: E/AndroidRuntime(1220): FATAL EXCEPTION: main
05-18 22:45:44.043: E/AndroidRuntime(1220): Process: sample.map.activity, PID: 1220
05-18 22:45:44.043: E/AndroidRuntime(1220): java.lang.RuntimeException: Unable to start activity ComponentInfo{sample.map.activity/sample.map.activity.MapActivity}: java.lang.NullPointerException
05-18 22:45:44.043: E/AndroidRuntime(1220):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
05-18 22:45:44.043: E/AndroidRuntime(1220):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
05-18 22:45:44.043: E/AndroidRuntime(1220):     at android.app.ActivityThread.access$800(ActivityThread.java:135)
05-18 22:45:44.043: E/AndroidRuntime(1220):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
05-18 22:45:44.043: E/AndroidRuntime(1220):     at android.os.Handler.dispatchMessage(Handler.java:102)
05-18 22:45:44.043: E/AndroidRuntime(1220):     at android.os.Looper.loop(Looper.java:136)
05-18 22:45:44.043: E/AndroidRuntime(1220):     at android.app.ActivityThread.main(ActivityThread.java:5017)
05-18 22:45:44.043: E/AndroidRuntime(1220):     at java.lang.reflect.Method.invokeNative(Native Method)
05-18 22:45:44.043: E/AndroidRuntime(1220):     at java.lang.reflect.Method.invoke(Method.java:515)
05-18 22:45:44.043: E/AndroidRuntime(1220):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
05-18 22:45:44.043: E/AndroidRuntime(1220):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
05-18 22:45:44.043: E/AndroidRuntime(1220):     at dalvik.system.NativeStart.main(Native Method)
05-18 22:45:44.043: E/AndroidRuntime(1220): Caused by: java.lang.NullPointerException
05-18 22:45:44.043: E/AndroidRuntime(1220):     at sample.map.activity.MapActivity.onCreate(MapActivity.java:39)
05-18 22:45:44.043: E/AndroidRuntime(1220):     at android.app.Activity.performCreate(Activity.java:5231)
05-18 22:45:44.043: E/AndroidRuntime(1220):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
05-18 22:45:44.043: E/AndroidRuntime(1220):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
05-18 23:04:59.383: W/ActivityThread(1354): ClassLoader.loadClass: The class loader returned by Thread.getContextClassLoader() may fail for processes that host multiple applications. You should explicitly specify a context class loader. For example: Thread.setContextClassLoader(getClass().getClassLoader());
05-18 23:04:59.813: I/Process(1354): Sending signal. PID: 1354 SIG: 9
05-18 23:05:01.123: D/dalvikvm(1401): GC_FOR_ALLOC freed 89K, 6% free 2960K/3128K, paused 26ms, total 28ms
05-18 23:05:01.123: I/dalvikvm-heap(1401): Grow heap (frag case) to 3.569MB for 635812-byte allocation
05-18 23:05:01.163: D/dalvikvm(1401): GC_FOR_ALLOC freed 2K, 5% free 3578K/3752K, paused 32ms, total 32ms
05-18 23:05:01.253: W/Visite Dates(1401): Reselected 0 tab name Unposted
05-18 23:05:01.463: D/(1401): HostConnection::get() New Host Connection established 0xb82b7f80, tid 1401
05-18 23:05:01.513: W/EGL_emulation(1401): eglSurfaceAttrib not implemented
05-18 23:05:01.523: D/OpenGLRenderer(1401): Enabling debug mode 0
05-18 23:51:25.343: W/EGL_emulation(1401): eglSurfaceAttrib not implemented
05-18 23:54:27.943: W/EGL_emulation(1401): eglSurfaceAttrib not implemented

Here is the xml file of my layout.

<?xml version="1.0" encoding="utf-8"?>
<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:name="com.google.android.gms.maps.MapFragment"/>

Okay, this stacktrace says the NPE occurs on the line #39 of your main activity. What do you have on that line? I suppose your map instance is null, so please share the layout you use for the main fragment. (layout/activity_map.xml). — rekaszeru, May 19 '14 at 04:31
Done the edit. It's the toast on line 38 line 39 is empty. That's probably causing the nullpoint. The long and lat must have returned null. — philip, May 19 '14 at 04:44

kgandroid · Answer 1 · 2014-05-19T04:47:53.863

I dont know what you have done in your xml file,but your xml file must look like this:

activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

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

</RelativeLayout>

Also Add the following,

< meta-data android:name="com.google.android.gms.version" 
         android:value="@integer/google_play_services_version" > 
< /meta-data>

in your manifest file immediately below the first meta-data tag(where you have placed your google api key).

Also I havent used the camera code that you have written to animate camera.My code:

CameraPosition cameraPosition = new CameraPosition.Builder().target(
                new LatLng(your_lat, your_long)).zoom(12).build();

map.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));

You can check out my edited post to see what the xml layout looks like. I already have that line of code in my xml and placed it under the api key meta data. It still shows the same error. The method that you suggested is not working since the lat and long are returning null. I can move the map to any coordinates I want by proving a lat and long value manually but that's not what I wanted. I wanted to get the actual lat ang long of the user programmatically. — philip, May 19 '14 at 04:55

score 0 · Accepted Answer · edited May 23 '17 at 11:50

0

Finally got it to work. It seems that the problem is the network provider.

Instead of using Criteria and getBestProvider I followed this approach. What it does is loop to a list of network provider and returns the best existing provider in your mobile phone manually.

edited May 23 '17 at 11:50

Community

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answered May 19 '14 at 06:02

philip

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Getting long and lat returns a nullpointexception in android map v2

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