App.java

public class App extends Application {
  private AppComponent appComponent;
  
  @Override
  public void onCreate() {
    appComponent = DaggerAppComponent
      .module1(new Module1())
      .etcModule(new EtcModule())
      .build();
  }
  
  private static App get(Context context) {
    return (App) context.getApplicationContext();
  }
  
  public static AppComponent getAppComponent(Context context) {
    return get(context).appComponent;
  }
}

SomeActivity.java

public class SomeActivity extends AppCompatActivity {
  @Override
  public void onCreate(Bundle bundle) {
    App.get(this)
      .inject(this);
  }
}