java.lang.IllegalStateException：来自错误线程的领域访问。 Realm 对象只能在创建它们的线程上访问

Question

我正在尝试将改造 2 与 RxJava 和 Realm 结合起来，方法是使用领域将改造可观察到的服务调用的响应保存到本地数据库。所以我得到一个异常，说 Realm 从不正确的线程访问。这是我的代码：

线索 1：

restApi.userEntityList()
            .map(userEntityDataMapper::transformAllToRealm)
            .doOnNext(userRealmModels -> {
                if (userRealmModels != null){
                    mRealm = Realm.getInstance(mContext);
                    mRealm.asObservable()
                            .map(realm -> mRealm.copyToRealmOrUpdate(userEntity))
                            .subscribe(new Subscriber<Object>() {
                                @Override
                                public void onCompleted() {

                                }

                                @Override
                                public void onError(Throwable e) {
                                    e.printStackTrace();
                                }

                                @Override
                                public void onNext(Object o) {
                                    Log.d("RealmManager", "user added!");
                                }
                            });
                }})
            .map(userEntityDataMapper::transformAll)
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(new Subscriber<List<User>>() {
                 @Override
                 public void onCompleted() {
                     hideViewLoading();
                 }

                 @Override
                 public void onError(Throwable e) {
                     hideViewLoading();
                     showErrorMessage(new DefaultErrorBundle((Exception) e));
                     showViewRetry();
                 }

                 @Override
                 public void onNext(List<User> users) {
                     showUsersCollectionInView(users);
                 }
            });

线索 2：

restApi.userEntityList()
            .map(userEntityDataMapper::transformAllToRealm)
            .doOnNext(userRealmModels -> {
                if (userRealmModels != null) {
                    mRealm = Realm.getInstance(mContext);
                    mRealm.beginTransaction();
                    mRealm.copyToRealmOrUpdate(userEntity);
                    mRealm.commitTransaction();
                }
            })
            .map(userEntityDataMapper::transformAll)
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(new Subscriber<List<User>>() {
                 @Override
                 public void onCompleted() {
                     hideViewLoading();
                 }

                 @Override
                 public void onError(Throwable e) {
                     hideViewLoading();
                     showErrorMessage(new DefaultErrorBundle((Exception) e));
                     showViewRetry();
                 }

                 @Override
                 public void onNext(List<User> users) {
                     showUsersCollectionInView(users);
                 }
            });

Logcat :

W/System.err: java.lang.IllegalStateException: Realm access from incorrect thread. Realm objects can only be accessed on the thread they were created.
at io.realm.BaseRealm.checkIfValid(BaseRealm.java:349)
at io.realm.BaseRealm.commitTransaction(BaseRealm.java:291)
at io.realm.Realm.commitTransaction(Realm.java:108)
at com.zeyad.cleanarchitecturet.data.db.RealmManagerImpl.put(RealmManagerImpl.java:66)
at com.zeyad.cleanarchitecturet.data.db.RealmManagerImpl.putAll(RealmManagerImpl.java:91)
at com.zeyad.cleanarchitecturet.data.repository.datasource.CloudUserDataStore.call(CloudUserDataStore.java:36)
at com.zeyad.cleanarchitecturet.data.repository.datasource.CloudUserDataStore.call(CloudUserDataStore.java:32)
at rx.Observable.onNext(Observable.java:4445)
at rx.internal.operators.OperatorDoOnEach.onNext(OperatorDoOnEach.java:80)
at rx.internal.operators.OperatorMap.onNext(OperatorMap.java:54)
at rx.internal.operators.OperatorMerge$MergeSubscriber.emitScalar(OperatorMerge.java:477)
at rx.internal.operators.OperatorMerge$MergeSubscriber.tryEmit(OperatorMerge.java:435)
at rx.internal.operators.OperatorMerge$MergeSubscriber.onNext(OperatorMerge.java:228)
at rx.internal.operators.OperatorMerge$MergeSubscriber.onNext(OperatorMerge.java:142)
at rx.internal.operators.OperatorMap.onNext(OperatorMap.java:54)
at retrofit.RxJavaCallAdapterFactory$CallOnSubscribe.call(RxJavaCallAdapterFactory.java:113)
at retrofit.RxJavaCallAdapterFactory$CallOnSubscribe.call(RxJavaCallAdapterFactory.java:88)
at rx.Observable.call(Observable.java:162)
at rx.Observable.call(Observable.java:154)
at rx.Observable.call(Observable.java:162)
at rx.Observable.call(Observable.java:154)
at rx.Observable.call(Observable.java:162)
at rx.Observable.call(Observable.java:154)
at rx.Observable.call(Observable.java:162)
at rx.Observable.call(Observable.java:154)
at rx.Observable.call(Observable.java:162)
at rx.Observable.call(Observable.java:154)
at rx.Observable.call(Observable.java:162)
at rx.Observable.call(Observable.java:154)
at rx.Observable.call(Observable.java:162)
at rx.Observable.call(Observable.java:154)
at rx.Observable.unsafeSubscribe(Observable.java:8098)
at rx.internal.operators.OperatorSubscribeOn.call(OperatorSubscribeOn.java:62)
at rx.internal.schedulers.ScheduledAction.run(ScheduledAction.java:55)
at rx.schedulers.ExecutorScheduler$ExecutorSchedulerWorker.run(ExecutorScheduler.java:98)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
Caused by: rx.exceptions.OnErrorThrowable$OnNextValue: OnError while emitting onNext value: java.util.ArrayList.class
at rx.exceptions.Exceptions.throwOrReport(Exceptions.java:187)
at rx.internal.operators.OperatorDoOnEach.onNext(OperatorDoOnEach.java:82)
... 29 more

Answer 1

我认为您已经使用主线程创建了 Realm 对象，并且正在另一个线程或后台线程中使用它。如果是这样，则在创建它们的同一个线程中使用它们。即

((Activity)mContext).runOnUiThread(new Runnable() {
   @Override
   public void run() {
        // You code of realm goes here
        if (userRealmModels != null) {
               mRealm = Realm.getInstance(mContext);
               mRealm.beginTransaction();
               mRealm.copyToRealmOrUpdate(userEntity);
               mRealm.commitTransaction();
         }
   }
});

Answer 2

我找到了修复方法。要将来自改造 2 的服务器响应保存到领域，然后传递给 UI。我通过像这样覆盖 Gson Builder 来改造 return 领域对象：

Retrofit.Builder()
            .baseUrl(RestApi.API_BASE_URL)
            .client(okHttpClient)
            .callbackExecutor(new JobExecutor())
            .addConverterFactory(GsonConverterFactory.create(new GsonBuilder()
                    .setExclusionStrategies(new ExclusionStrategy() {
                        @Override
                        public boolean shouldSkipField(FieldAttributes f) {
                            return f.getDeclaringClass().equals(RealmObject.class);
                        }

                        @Override
                        public boolean shouldSkipClass(Class<?> clazz) {
                            return false;
                        }
                    }).create()))
            .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
            .build();

然后：

restApi.userRealmList()
    .doOnNext(userRealmModels -> {
        if (userRealmModels != null) {
            Realm realm = Realm.getInstance(mContext);
            realm.beginTransaction();
            realm.copyToRealmOrUpdate(userRealmModels);
            realm.commitTransaction();
            realm.close();
        }})
    .map(userEntityDataMapper::transformAll)
    .subscribeOn(Schedulers.io())
    .observeOn(AndroidSchedulers.mainThread())
    .subscribe(new Subscriber<List<User>>() {
         @Override
         public void onCompleted() {
             hideViewLoading();
         }

         @Override
         public void onError(Throwable e) {
             hideViewLoading();
             showErrorMessage(new DefaultErrorBundle((Exception) e));
             showViewRetry();
         }

         @Override
         public void onNext(List<User> users) {
             showUsersCollectionInView(users);
         }
    });

java.lang.IllegalStateException：来自错误线程的领域访问。 Realm 对象只能在创建它们的线程上访问

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

multithreading

android

realm

rx-java

retrolambda