Question

在我的Google Play控制台上，自从我开始使用Dagger 2以来，我看到了很多崩溃报告，但仅限于Android 7.0，主要是三星设备，一些Huawai和Motorola设备以及一些罕见的Xperia设备：

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)

我无法重现这个问题，因为我手头没有任何受影响的设备，似乎并非所有类型的设备都受到影响，更像是随机启动失败。

从我从研究中学到的是，在活动实际附加到应用程序之前，很可能会调用活动onCreate。但我无法证明这一说法......

我正在关注Google的MVP + Dagger架构蓝图。

我的申请类：

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;
    }

}

我的MainActivity类：

public class MainActivity extends DaggerAppCompatActivity {

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

}

相关的Dagger 2代码：

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())); 
    }

我不知道如何解决此崩溃问题，但崩溃的数量太大而无法忽略。由于我的Dagger 2使用完全适用于所有其他Android版本和设备，我认为它不是由我使用Dagger 2的方式引起的，而是由某些特定于供应商的7.0实现引起的。如果有人遇到同样的问题并找到解决方案，请，请帮助我！

由于这个错误让我疯狂，我向100k用户推出了一个测试版本，试图了解整个问题出在哪里。

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);
    }

}

该活动基于Dagger的内联AndroidInjection代码活动。我的想法是，如果使用ApplicationContext而不是getApplication()来解决此问题，我的堆栈跟踪应详细说明最新情况：

如果问题是由getApplication()导致堆栈跟踪包含injectWithNullApplication()或injectWithWrongApplication()
抛出的NPE会显示getApplicationContext()返回null
抛出的RuntimeException会显示getApplicationContext()不是我的应用程序
如果不会抛出任何异常，getApplication()或getApplicationContext()都会返回我的申请，我不在乎实际解决了什么问题

这是堆栈跟踪：

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)

因此!(application instanceof HasActivityInjector)中的if子句inject()没有重新路由到injectWithWrongApplication()，但同一个if子句导致同一个Application实例上的injectNow(Application application)中的RuntimeException。 WTF？我的代码看起来像100次，但如果我有错误，请告诉我！否则，我猜在7.0的某些Vendor实现中有一些非常奇怪的事情可能无法修复......

根据对https://github.com/google/dagger/issues/748的讨论，我还推出了一个测试版本，该版本仅在所有Dagger组件中使用getApplicationContext()而不是getApplication()而没有任何差异。

我在清单中的应用标记

<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>

Answer 1

最后，我找到了一种方法来解决因在我的应用程序中使用Android 7.0下的Dagger 2而导致的崩溃。请注意，这无法解决在Android 7.0 下未正确使用自定义应用程序的问题。在我的情况下，除了实现Dagger 2之外，我的自定义应用程序中没有重要的逻辑，所以我只是将基于DaggerApplication的实现替换为下面的ApplicationlessInjection。

已知问题

自定义应用程序类中没有依赖注入（无论如何，这对于令人讨厌的Android 7.0 OEM实现来说可能不是一个好主意）
并非所有Dagger组件都由我修改过，我只替换了DaggerAppCompatActivity，DaggerIntentService和DaggerFragment。如果您正在使用其他组件，例如DaggerDialogFragment或DaggerBroadcastReceiver，则需要创建自己的工具，但我想这不应该太难：）

<强>实施

停止使用DaggerApplication。从标准Application再次扩展自定义应用程序或完全删除自定义应用程序。对于Dagger 2的依赖注入，它不再需要了。只需延伸FixedDaggerAppCompatActivity你可以和Dagger 2 DI一起参加活动。

您可能会注意到我仍在将应用程序上下文传递给ApplicationlessInjection.getInstance()。依赖注入本身根本不需要上下文，但我希望能够轻松地将应用程序上下文注入到我的其他组件和模块中。在那里我不关心应用程序上下文是我的自定义应用程序还是来自Android 7.0的一些疯狂的其他东西，只要它是一个上下文。

<强> 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;
    }

}

<强> 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);
    }

}

<强> 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()));
    }

}

<强> 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);
    }

}

我的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();

    }

}

我的AppModule

@Module
public abstract class AppModule {

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

}

为了完整起见，我的@ApplicationContext注释

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

希望我也能用我的代码帮助别人。对我来说，我可以解决与引入Dagger 2和奇怪的Android 7.0版本相关的所有崩溃。

如果需要更多说明，请告诉我！

Answer 2

我在我的应用中遇到了同样的问题，我使用下面的代码解决了它：

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

Android 7.0和三星设备上使用Dagger 2的RuntimeException

2 个答案: