Realm access from incorrect thread in rx and dagger

问题:

I know this question asks a lot but i am confused by reading this question.In my project i am using dagger, rx and realm in mvp pattern.I have an application with a LoginActivity that when the user login correctly, the user information that comes from server store in realm in this page and user jumps to MainActivity.In MainActivity i want this user info but i got this error:

java.lang.IllegalStateException: Realm access from incorrect thread. Realm objects can only be accessed on the thread they were created.

I know that :

Realm access from incorrect thread. Realm objects can only be accessed on the thread they were created.

In my Appliction class i have initialized DaggerAplicationComponnet.I have applicationModule:

@AppScope @Component(modules = {ApplicationModule.class, NetworkModule.class , AppRealmModule.class}) public interface ApplicationComponent {     Realm getRealm();     ... } 

and AppRealmModule:

@Module public class AppRealmModule {      @Provides     @AppScope     Realm provideRealm (Context context) {         Realm.init(context);         RealmConfiguration realmConfiguration = new RealmConfiguration.Builder()                 .deleteRealmIfMigrationNeeded()                 .name("Payeshdb")                 .build();         Realm.setDefaultConfiguration(realmConfiguration);         return Realm.getDefaultInstance();     } 

That means , i create realm instance on ui thread.Now in MainActivity i have read realm:

@Override public Observable<User> findUser() {     return Observable.create(new ObservableOnSubscribe<User>() {         @Override         public void subscribe(ObservableEmitter<User> emitter) throws Exception {             try {                 User user = realm.where(User.class).findFirst();                 User user1 = realm.copyFromRealm(user);                 emitter.onNext(user1);                 emitter.onComplete();              }catch (Exception e) {                 emitter.onError(e);             }         }     }); } 

Now, in presenter i am using rx in this way:

userRepository.findUser()                 .subscribeOn(Schedulers.io())                 .observeOn(AndroidSchedulers.mainThread())                 .subscribe(new DisposableObserver<User>() {                     @Override                     public void onNext(User user) {                      }                      @Override                     public void onError(Throwable e) {                       // got error: Realm access from incorrect thread.                     }                      @Override                     public void onComplete() {                      }                 }); 

this is a place that i got above error. In some post i have read this:

Use copyFromRealm to get the data from realm which will return them as plain objects rather than realm objects.

And i do that but i still got error.

Is it possible initialize realm with dagger and use different thread for crud operation?

What is your suggestion?

回答1:

@Override public Observable<User> findUser() {   return Observable.create(new ObservableOnSubscribe<User>() {     @Override     public void subscribe(ObservableEmitter<User> emitter) throws Exception {         try(Realm realm = Realm.getDefaultInstance()) {             realm.refresh();             User user = realm.where(User.class).findFirst();             User user1 = realm.copyFromRealm(user);             emitter.onNext(user1);             emitter.onComplete();         } catch (Exception e) {             emitter.onError(e);         }     }   }); } 

回答2:

As the error says

Realm objects can only be accessed on the thread they were created

So just subscribe on the same thread you created Realm

userRepository.findUser()             .subscribeOn(AndroidSchedulers.mainThread())             .observeOn(AndroidSchedulers.mainThread()) 

文章来源: Realm access from incorrect thread in rx and dagger