java.lang.NullPointerException when getting location

I have some problems im not able to recreate in emulator, but i keep getting error reports in android market that i have no clue how to solve... anyone else that might see it id be wery greatful

Sometimes this reposrts

java.lang.NullPointerException
at android.webkit.WebViewDatabase.getCacheTotalSize(WebViewDatabase.java:734)
at android.webkit.CacheManager.trimCacheIfNeeded(CacheManager.java:548)
at android.webkit.WebViewWorker.handleMessage(WebViewWorker.java:190)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:123)
at android.os.HandlerThread.run(HandlerThread.java:60)

And sometimes this report

java.lang.RuntimeException: Unable to start activity ComponentInfo{polis.koll/polis.koll.WebPageLoader}: java.lang.IllegalArgumentException: provider==null
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2737)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2753)
at android.app.ActivityThread.access$2500(ActivityThread.java:129)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2107)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:143)
at android.app.ActivityThread.main(ActivityThread.java:4701)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:521)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.IllegalArgumentException: provider==null
at android.location.LocationManager.requestLocationUpdates(LocationManager.java:625)
at polis.koll.WebPageLoader.getLocation(WebPageLoader.java:54)
at polis.koll.WebPageLoader.onCreate(WebPageLoader.java:70)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2701)

Here is my code

    public class WebPageLoader extends Activity implements LocationListener{
    public static String Android_ID = null;
    final Activity activity = this;
    private Location mostRecentLocation;

    private void CheckEnableGPS(){
        String provider = Settings.Secure.getString(getContentResolver开发者_高级运维(),
          Settings.Secure.LOCATION_PROVIDERS_ALLOWED);
           if(!provider.equals("")){
               //GPS Enabled
               getLocation();
           }else{
            Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
               startActivity(intent);
           }

       }


private void getLocation() {
    String provider = Settings.Secure.getString(getContentResolver(),
          Settings.Secure.LOCATION_PROVIDERS_ALLOWED);
           if(!provider.equals("")){
    LocationManager locationManager =
      (LocationManager)getSystemService(Context.LOCATION_SERVICE);
    Criteria criteria = new Criteria();
    criteria.setAccuracy(Criteria.ACCURACY_FINE);
    String bestprovider = locationManager.getBestProvider(criteria,true);
    locationManager.requestLocationUpdates(bestprovider, 1, 500, this);     
    mostRecentLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
         }else{
            Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
               startActivity(intent);
           }
  }

@Override
public void onCreate(Bundle savedInstanceState)
{
    //AdManager.setTestDevices( new String[] { AdManager.TEST_EMULATOR } );
    super.onCreate(savedInstanceState);
    this.getWindow().requestFeature(Window.FEATURE_PROGRESS);
    setContentView(R.layout.main);

    getLocation();
    Android_ID = Secure.getString(getContentResolver(), Secure.ANDROID_ID);


    WebView webView = (WebView) findViewById(R.id.webView);
    webView.getSettings().setJavaScriptEnabled(true);
    /** Allows JavaScript calls to access application resources **/
    webView.addJavascriptInterface(new JavaScriptInterface(), "android16");
    webView.setWebChromeClient(new WebChromeClient() {
        public void onProgressChanged(WebView view, int progress)
        {
            activity.setTitle("Letar poliskontroller");
            activity.setProgress(progress * 100);


            if(progress == 100)
                activity.setTitle(R.string.app_name);
        }
    });


    webView.setWebViewClient(new WebViewClient() {

        @Override
        public void onReceivedError(WebView view, int errorCode, String description, String failingUrl)
        {
            // Handle the error
        }


     // Testade att ta bort denna override för att få market länkar att fungera
     //   @Override
     //   public boolean shouldOverrideUrlLoading(WebView view, String url)
     //   {
     //       view.loadUrl(url);
     //       return true;
     //   }
    });

    if (Locale.getDefault().getLanguage().equals("sv")){
    //webView.loadUrl("file:///android_asset/android.html");
        webView.loadUrl("file:///android_asset/findgps_sv.html");
    }else{
    //webView.loadUrl("http://m.bryggplatsen.se/android/polis/index.php");
    //webView.loadUrl("file:///android_asset/android_en.html");
        webView.loadUrl("file:///android_asset/findgps_en.html");
    }



}
    /** Sets up the interface for getting access to Latitude and Longitude data from device
     **/




private class JavaScriptInterface {
    public double getLatitude(){
        return mostRecentLocation != null ? mostRecentLocation.getLatitude() : Double.NaN;
    }

    public double getLongitude(){
        return mostRecentLocation != null ? mostRecentLocation.getLongitude() : Double.NaN;
    }


    public String getAndroid_ID(){
        return Android_ID;
    }

     public void sharethisapp(){
     startActivity(Intent.createChooser(sharespotIntent(), "Share this warning"));
     }
  }


@Override
public void onLocationChanged(Location location) {
    // TODO Auto-generated method stub

    getLocation();
    //CheckEnableGPS();
}

@Override
public void onProviderDisabled(String provider) {
    // TODO Auto-generated method stub
    getLocation();
}

@Override
public void onProviderEnabled(String provider) {
    // TODO Auto-generated method stub
    getLocation();
}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
    // TODO Auto-generated method stub
    getLocation();
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    super.onCreateOptionsMenu(menu);
    MenuItem item = menu.add("Shut down");
    item.setIcon(R.drawable.exit);

    item = menu.add("Share");
    item.setIcon(R.drawable.m_share);

    item = menu.add("Fix GPS");
    item.setIcon(R.drawable.globe);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    if (item.getTitle() == "Shut down") {
        System.exit(0);
        finish();
    }
    if (item.getTitle() == "Fix GPS") {
        getLocation();
    }
    if (item.getTitle() == "Share") {
        if (Locale.getDefault().getLanguage().equals("sv")){
        startActivity(Intent.createChooser(shareIntent(), "Dela denna app"));
        }else{
        startActivity(Intent.createChooser(shareIntent(), "Share this app"));
        }
    }
    return true;
}

private Intent shareIntent() {
        Intent shareIntent = new Intent(android.content.Intent.ACTION_SEND);
        shareIntent.setType("text/plain");      
    if (Locale.getDefault().getLanguage().equals("sv")){
        shareIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, "Testa denna android app...");
        return shareIntent.putExtra(android.content.Intent.EXTRA_TEXT, "index.php");
    }else{
        shareIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, "Try this cool android app...");
        return shareIntent.putExtra(android.content.Intent.EXTRA_TEXT, "index_en.php");         
    }

}


private Intent sharespotIntent() {
    Intent sharespotIntent = new Intent(android.content.Intent.ACTION_SEND);
    sharespotIntent.setType("text/plain");      
if (Locale.getDefault().getLanguage().equals("sv")){
    sharespotIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, " la just upp en ny varning i appen Polisradar");
    return sharespotIntent.putExtra(android.content.Intent.EXTRA_TEXT, "warn.php?lat=" + mostRecentLocation.getLatitude() + "&lng=" + mostRecentLocation.getLongitude() + "");
}else{
    sharespotIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, " just added a new warning in the app Policeradar");
    return sharespotIntent.putExtra(android.content.Intent.EXTRA_TEXT, "warn_en.php?lat=" + mostRecentLocation.getLatitude() + "&lng=" + mostRecentLocation.getLongitude() + "");       
    }
}

}

The method Settings.Secure.getString() can return null if the requested name is not in the data base. I don't know why Settings.Secure.LOCATION_PROVIDERS_ALLOWED wouldn't be found, though. However, your code does not check (in getLocation()) that provider isn't null before checking that it isn't the empty string. I think that's the source of your second exception.

Seemingly random errors deep in the framework can also be caused by trying to run your app on an OS release that doesn't support something in your code. Make sure that your code compiles against the minSdkVersion you have set in your manifest, not just the targetSdkVersion.

One note on this issue. I don't know if this was your problem or not but I was looking at sharing some files between applications and tried modifying the android:sharedUserId attribute in my AndroidManifest.xml file. Once I did that I got exactly the same error you reported and my app failed to start up properly (due to a failure in AdRequest, it seems). Even after removing the sharedUserId attribute from the manifest I continued to get errors, though I think it was from the preferences database.

The bottom line is don't change the sharedUserId attribute of an application once it has been deployed or you will require an uninstall/reinstall cycle to get everything working again.