对“this”的方法调用的NullPointerException

Question

在我的android项目中，当调用我的一个对象调用一个方法时，我在crashlytics和play store中报告了一个间歇性的NullPointerException以获取空指针异常。

以下是具有NullPointerException的方法的全部内容：

@Override
public void notifyActivityStarted() {
    startUpdatingLocation(); // <-- NullPointerException occurs here.  This is line 83 of DefaultAndroidLocationProvider.java
}

private void startUpdatingLocation() {
    final String bestProvider = getBestProviderName();
    Log.d(LOGTAG, "Starting to update location for provider: " + bestProvider);

    // If we don't have a location yet, then let's make sure we get one at
    // least
    // temporarily.
    Location currentLoc = getLastLocationFromBestProvider();
    if (currentLoc != null) {
        Log.d(LOGTAG, "Hydrating with last location");
        mLastLocation.hydrate(currentLoc);
    }

    mWorker = new WorkerThread("DefaultAndroidLocation");

    // Get a location update every 10s from both network and GPS.
    if (mManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
        mManager.requestLocationUpdates(
            LocationManager.GPS_PROVIDER,
            10000,
            0,
            DefaultAndroidLocationProvider.this,
            mWorker.getLooper());
    }
    if (mManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)) {
        mManager.requestLocationUpdates(
            LocationManager.NETWORK_PROVIDER,
            10000,
            0,
            DefaultAndroidLocationProvider.this,
            mWorker.getLooper());
    }

    mIsUpdatingLocation = true;
    shutdownInitiated = false;
}

这是堆栈跟踪：

java.lang.NullPointerException
       at com.jingit.mobile.location.DefaultAndroidLocationProvider.notifyActivityStarted(DefaultAndroidLocationProvider.java:83)
       at com.jingit.mobile.location.ActivityObserverSet.onStartObserved(ActivityObserverSet.java:48)
       at com.jingit.mobile.location.LocationAwareFragment.onStart(LocationAwareFragment.java:41)
       at android.support.v4.app.Fragment.performStart(Fragment.java:1484)
       at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:941)
       at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1088)
       at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
       at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1444)
       at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:429)
       at android.os.Handler.handleCallback(Handler.java:733)
       at android.os.Handler.dispatchMessage(Handler.java:95)
       at android.os.Looper.loop(Looper.java:157)
       at android.app.ActivityThread.main(ActivityThread.java:5633)
       at java.lang.reflect.Method.invokeNative(Method.java)
       at java.lang.reflect.Method.invoke(Method.java:515)
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:896)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:712)
       at dalvik.system.NativeStart.main(NativeStart.java)

我无法找到任何有关NullPointerException文档的提示，但未能找到任何其他有用的提示。任何想法或想法将不胜感激。