RuntimeException with Dagger 2 on Android 7.0 and

问题:

On my Google Play console I see quite a lot crash reports since I started to use Dagger 2, but only on Android 7.0 and mainly on Samsung devices, some Huawai and Motorola devices and some rare Xperia devices:

java.lang.RuntimeException: 
  at android.app.ActivityThread.performLaunchActivity (ActivityThread.java:2984)
  at android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:3045)
  at android.app.ActivityThread.-wrap14 (ActivityThread.java)
  at android.app.ActivityThread$H.handleMessage (ActivityThread.java:1642)
  at android.os.Handler.dispatchMessage (Handler.java:102)
  at android.os.Looper.loop (Looper.java:154)
  at android.app.ActivityThread.main (ActivityThread.java:6776)
  at java.lang.reflect.Method.invoke (Method.java)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:1518)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1408)
Caused by: java.lang.RuntimeException: 
  at dagger.android.AndroidInjection.inject (AndroidInjection.java:48)
  at dagger.android.support.DaggerAppCompatActivity.onCreate (DaggerAppCompatActivity.java:43)
  at com.package.MainActivity.onCreate (MainActivity.java:83)
  at android.app.Activity.performCreate (Activity.java:6956)
  at android.app.Instrumentation.callActivityOnCreate (Instrumentation.java:1126)
  at android.app.ActivityThread.performLaunchActivity (ActivityThread.java:2927)

I cannot reproduce the issue since I do not have any affected device at hand, also it seems that not all devices of a type are affected, more like a random startup failure.

From what I learned through research is that most likely the activity's onCreate is called before the activity is actually attached to an application. But I cannot prove this statement...

I am following Google's architecture blueprint for MVP+Dagger.

My Application class:

public class App extends DaggerApplication {

    @Override
    public void onCreate() {
        super.onCreate();
    }

    @Override
    protected AndroidInjector<? extends DaggerApplication> applicationInjector() {
        AppComponent appComponent = DaggerAppComponent.builder().application(this).build();
        appComponent.inject(this);
        return appComponent;
    }

}

My MainActivity class:

public class MainActivity extends DaggerAppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

}

Relevant Dagger 2 code:

DaggerAppCompatActivity: https://github.com/google/dagger/blob/e8d7cd4c29c1316c5bb1cf0737d4f29111fcb1c8/java/dagger/android/support/DaggerAppCompatActivity.java#L42-L45

protected void onCreate(@Nullable Bundle savedInstanceState) { 
    AndroidInjection.inject(this); 
    super.onCreate(savedInstanceState); 
}

AndroidInjection: https://github.com/google/dagger/blob/e8d7cd4c29c1316c5bb1cf0737d4f29111fcb1c8/java/dagger/android/AndroidInjection.java#L43-L52

public static void inject(Activity activity) { 
    checkNotNull(activity, "activity"); 
    Application application = activity.getApplication(); 
    if (!(application instanceof HasActivityInjector)) { 
        throw new RuntimeException( 
            String.format( 
                "%s does not implement %s", 
                application.getClass().getCanonicalName(), 
                HasActivityInjector.class.getCanonicalName())); 
    }

I have no idea how to resolve this crash, but the amount of crashes is too significant to ignore. Since my Dagger 2 usage works perfectly on all other Android versions and devices I assume that it is not caused by the way I use Dagger 2 but somehow by some vendor specific 7.0 implementations. If anybody faced the same issue and found a solution please, please, please help me!

Since this error is driving me nuts I rolled out a test version to 100k users trying to understand where this whole thing goes wrong.

public abstract class TestDaggerAppCompatActivity extends AppCompatActivity implements HasFragmentInjector, HasSupportFragmentInjector {

    @Inject DispatchingAndroidInjector<Fragment> supportFragmentInjector;
    @Inject DispatchingAndroidInjector<android.app.Fragment> frameworkFragmentInjector;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        inject();
        super.onCreate(savedInstanceState);
    }

    @Override
    public AndroidInjector<Fragment> supportFragmentInjector() {
        return supportFragmentInjector;
    }

    @Override
    public AndroidInjector<android.app.Fragment> fragmentInjector() {
        return frameworkFragmentInjector;
    }

    private void inject() {
        Application application = getApplication();

        if(application == null) {
            injectWithNullApplication();
            return;
        }

        if (!(application instanceof HasActivityInjector)) {
            injectWithWrongApplication();
            return;
        }

        // Everything seems ok...
        injectNow(application);
    }

    private void injectWithNullApplication() {
        Application application = (Application) getApplicationContext();
        injectNow(application);
    }

    private void injectWithWrongApplication() {
        Application application = (Application) getApplicationContext();
        injectNow(application);
    }

    private void injectNow(Application application) {
        checkNotNull(application, "Application must not be null");

        if (!(application instanceof HasActivityInjector)) {
            throw new RuntimeException(String.format("%s does not implement %s", application.getClass().getCanonicalName(), HasActivityInjector.class.getCanonicalName()));
        }

        AndroidInjector<Activity> activityInjector = ((HasActivityInjector) application).activityInjector();
        checkNotNull(activityInjector, "%s.activityInjector() returned null", application.getClass().getCanonicalName());

        activityInjector.inject(this);
    }

}

The activity is based on Dagger's activity with inlined AndroidInjection code. My thinking was that if this issue would not be resolved by using ApplicationContext instead of getApplication() my stack traces should detail whats going on:

• if the issue is caused by getApplication() the stack trace would contain injectWithNullApplication() or injectWithWrongApplication()
• a thrown NPE would show that getApplicationContext() returned null
• a thrown RuntimeException would show that the getApplicationContext() is not my Application
• if no exception would be thrown either the getApplication() or getApplicationContext() returned my application and I would not care what actually solved the issue

And here is the stack trace:

Caused by: java.lang.RuntimeException: 
  at com.package.di.TestDaggerAppCompatActivity.inject (TestDaggerAppCompatActivity.java:49)
  at com.package.di.TestDaggerAppCompatActivity.onCreate (TestDaggerAppCompatActivity.java:31)
  at com.package.MainActivity.onCreate (MainActivity.java:83)
  at android.app.Activity.performCreate (Activity.java:6942)
  at android.app.Instrumentation.callActivityOnCreate (Instrumentation.java:1126)
  at android.app.ActivityThread.performLaunchActivity (ActivityThread.java:2880)

So the if clause !(application instanceof HasActivityInjector) in inject() did not reroute to injectWithWrongApplication() but the same if clause caused the RuntimeException in injectNow(Application application) on the same Application instance. WTF? I looked like 100 times at my code but if I have an error in there please let me know! Otherwise, I guess there are some really weird things going on in some Vendor implementations of 7.0 which are maybe not fixable...

Based on the discussions on https://github.com/google/dagger/issues/748 I also rolled out a test version that only uses getApplicationContext() instead of getApplication() in all Dagger components without any difference.

My application tag from manifest

<application
    android:name=".App"
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/SplashScreenTheme"
    android:fullBackupContent="false">

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

    <meta-data android:name="android.max_aspect" android:value="2.1" />

    <activity
        android:name="com.package.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>

    <service android:name="com.package.GeneratorService" android:exported="false"/>
</application>

回答1:

Finally I found a way to resolve the crashes caused by using Dagger 2 under Android 7.0 for my application. Please note that this does not resolve the issue with a custom application not being properly used under Android 7.0. In my case I did not have important logic in my custom Application besides getting Dagger 2 implemented and so I just replaced the DaggerApplication based implementation with the ApplicationlessInjection below.

Known issues

• No dependency injection in custom application classes (probably this isn't a good idea with the freaking Android 7.0 OEM implementations anyway)
• Not all Dagger components where modified by me, I replaced only DaggerAppCompatActivity, DaggerIntentService and DaggerFragment. If you are using other components like DaggerDialogFragment or DaggerBroadcastReceiver you need to create your own implements but I guess that should not be too hard :)

Implementation

Stop using DaggerApplication. Either extend your custom application again from the standard Application or get rid of the custom application entirely. For the dependency injection with Dagger 2 its not needed anymore. Just extend e.g. FixedDaggerAppCompatActivity and you are good to go with the Dagger 2 DI for activities.

You may notice that I am still passing the application context to the ApplicationlessInjection.getInstance(). The dependency injection itself does not need the context at all but I want to be able to easily inject the application context into my other components and modules. And there I do not care if the application context is my custom App or some crazy other stuff from Android 7.0 as long as it is a context.

ApplicationlessInjection

public class ApplicationlessInjection
        implements
            HasActivityInjector,
            HasFragmentInjector,
            HasSupportFragmentInjector,
            HasServiceInjector,
            HasBroadcastReceiverInjector,
            HasContentProviderInjector {

    private static ApplicationlessInjection instance = null;

    @Inject DispatchingAndroidInjector<Activity> activityInjector;
    @Inject DispatchingAndroidInjector<BroadcastReceiver> broadcastReceiverInjector;
    @Inject DispatchingAndroidInjector<android.app.Fragment> fragmentInjector;
    @Inject DispatchingAndroidInjector<Fragment> supportFragmentInjector;
    @Inject DispatchingAndroidInjector<Service> serviceInjector;
    @Inject DispatchingAndroidInjector<ContentProvider> contentProviderInjector;

    public ApplicationlessInjection(Context applicationContext) {
        AppComponent appComponent = DaggerAppComponent.builder().context(applicationContext).build();
        appComponent.inject(this);
    }

    @Override
    public DispatchingAndroidInjector<Activity> activityInjector() {
        return activityInjector;
    }

    @Override
    public DispatchingAndroidInjector<android.app.Fragment> fragmentInjector() {
        return fragmentInjector;
    }

    @Override
    public DispatchingAndroidInjector<Fragment> supportFragmentInjector() {
        return supportFragmentInjector;
    }

    @Override
    public DispatchingAndroidInjector<BroadcastReceiver> broadcastReceiverInjector() {
        return broadcastReceiverInjector;
    }

    @Override
    public DispatchingAndroidInjector<Service> serviceInjector() {
        return serviceInjector;
    }

    @Override
    public AndroidInjector<ContentProvider> contentProviderInjector() {
        return contentProviderInjector;
    }

    public static ApplicationlessInjection getInstance(Context applicationContext) {
        if(instance == null) {
            synchronized(ApplicationlessInjection.class) {
                if (instance == null) {
                    instance = new ApplicationlessInjection(applicationContext);
                }
            }
        }

        return instance;
    }

}

FixedDaggerAppCompatActivity

public abstract class FixedDaggerAppCompatActivity extends AppCompatActivity implements HasFragmentInjector, HasSupportFragmentInjector {

    @Inject DispatchingAndroidInjector<Fragment> supportFragmentInjector;
    @Inject DispatchingAndroidInjector<android.app.Fragment> frameworkFragmentInjector;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        inject();
        super.onCreate(savedInstanceState);
    }

    @Override
    public AndroidInjector<Fragment> supportFragmentInjector() {
        return supportFragmentInjector;
    }

    @Override
    public AndroidInjector<android.app.Fragment> fragmentInjector() {
        return frameworkFragmentInjector;
    }

    private void inject() {
        ApplicationlessInjection injection = ApplicationlessInjection.getInstance(getApplicationContext());

        AndroidInjector<Activity> activityInjector = injection.activityInjector();

        if (activityInjector == null) {
            throw new NullPointerException("ApplicationlessInjection.activityInjector() returned null");
        }

        activityInjector.inject(this);
    }

}

FixedDaggerFragment

public abstract class FixedDaggerFragment extends Fragment implements HasSupportFragmentInjector {

    @Inject DispatchingAndroidInjector<Fragment> childFragmentInjector;

    @Override
    public void onAttach(Context context) {
        inject();
        super.onAttach(context);
    }

    @Override
    public AndroidInjector<Fragment> supportFragmentInjector() {
        return childFragmentInjector;
    }


    public void inject() {
        HasSupportFragmentInjector hasSupportFragmentInjector = findHasFragmentInjector();

        AndroidInjector<Fragment> fragmentInjector = hasSupportFragmentInjector.supportFragmentInjector();

        if (fragmentInjector == null) {
            throw new NullPointerException(String.format("%s.supportFragmentInjector() returned null", hasSupportFragmentInjector.getClass().getCanonicalName()));
        }

        fragmentInjector.inject(this);
    }

    private HasSupportFragmentInjector findHasFragmentInjector() {
        Fragment parentFragment = this;

        while ((parentFragment = parentFragment.getParentFragment()) != null) {
            if (parentFragment instanceof HasSupportFragmentInjector) {
                return (HasSupportFragmentInjector) parentFragment;
            }
        }

        Activity activity = getActivity();

        if (activity instanceof HasSupportFragmentInjector) {
            return (HasSupportFragmentInjector) activity;
        }

        ApplicationlessInjection injection = ApplicationlessInjection.getInstance(activity.getApplicationContext());
        if (injection != null) {
            return injection;
        }

        throw new IllegalArgumentException(String.format("No injector was found for %s", getClass().getCanonicalName()));
    }

}

FixedDaggerIntentService

public abstract class FixedDaggerIntentService extends IntentService {

    public FixedDaggerIntentService(String name) {
        super(name);
    }

    @Override
    public void onCreate() {
        inject();
        super.onCreate();
    }

    private void inject() {
        ApplicationlessInjection injection = ApplicationlessInjection.getInstance(getApplicationContext());

        AndroidInjector<Service> serviceInjector = injection.serviceInjector();

        if (serviceInjector == null) {
            throw new NullPointerException("ApplicationlessInjection.serviceInjector() returned null");
        }

        serviceInjector.inject(this);
    }

}

My AppComponent

@Singleton
@Component(modules = {
        AppModule.class,
        ActivityBindingModule.class,
        AndroidSupportInjectionModule.class
})
public interface AppComponent extends AndroidInjector<ApplicationlessInjection> {

    @Override
    void inject(ApplicationlessInjection instance);

    @Component.Builder
    interface Builder {

        @BindsInstance
        AppComponent.Builder context(Context applicationContext);

        AppComponent build();

    }

}

My AppModule

@Module
public abstract class AppModule {

    @Binds
    @ApplicationContext
    abstract Context bindContext(Context applicationContext);

}

And for the sake of completeness my @ApplicationContext annotation

@Qualifier
@Retention(RetentionPolicy.RUNTIME)
public @interface ApplicationContext {}

---

Hopefully I can help someone else with my code as well. For me I could resolve all crashes related to introducing Dagger 2 and the weird Android 7.0 versions.

If more clarification is needed just let me know!

回答2:

I encountered the same problem in my app and i resolved it by using below code :

Application app = activity.getApplication();
if(app == null) {
     app = (Application)activity.getApplicationContext();
}