Question

我正在尝试调用Web服务来获取数据，并使用以下代码将其存储到数据库中。我创建了一个单独的类来执行以下操作。

现在，问题是当我成功获取数据并将其存储在数据库中时，我想通知我的活动。如果发生某些错误，那么我想在UI本身上显示出来。

我能够以某种方式编写代码以使用分页获取数据，但不确定如何通知UI可以订阅的UI捕获与进度和错误相关的更新（如果有）。

$ sed 's/@/@A/g; s/{/@B/g; s/}/@C/g; s/foo/{/g; s/bar/}/g; s/{[^{}]*}/<&>/2; s/}/bar/g; s/{/foo/g; s/@C/}/g; s/@B/{/g; s/@A/@/g' file
ABC foo DEF bar GHI <foo KLM bar> NOP foo QRS bar TUV

已更新

创建了public Flowable<Response> getFitnessData() { Request request = new Request(); request.setAccess_token("d80fa6bd6f78cc704104d61146c599bc94b82ca225349ee68762fc6c70d2dcf0"); Flowable<Response> fitnessFlowable = new WebRequest() .getRemoteClient() .create(FitnessApi.class) .getFitnessData("5b238abb4d3590001d9b94a8",request.toMap()); fitnessFlowable.subscribeOn(Schedulers.io()) .observeOn(AndroidSchedulers.mainThread()) .takeUntil(response->response.getSummary().getNext()!=null) .subscribe(new Subscriber<Response>() { @Override public void onSubscribe(Subscription s) { s.request(Long.MAX_VALUE); } @Override public void onNext(Response response) { Log.e(TAG, "onNext" ); if(response !=null){ if(response.getFitness()!=null && response.getFitness().size()!=0){ Realm realm = Realm.getDefaultInstance(); realm.executeTransactionAsync(new Realm.Transaction() { @Override public void execute(Realm realm) { realm.copyToRealmOrUpdate(response.getFitness()); } }, new Realm.Transaction.OnSuccess() { @Override public void onSuccess() { Log.i(TAG, "onSuccess , fitness data saved"); } }, new Realm.Transaction.OnError() { @Override public void onError(Throwable error) { Log.i(TAG, "onError , fitness data failed to save"+error.getMessage() ); } }); }else{ Log.i(TAG, "onError , no fitness data available" ); } }else{ Log.i(TAG, "onError , response is null" ); } } @Override public void onError(Throwable t) { Log.e(TAG, "onError" +t.getMessage()); } @Override public void onComplete() { Log.e(TAG, "onComplete"); } });; return null; }，以在UI上传播事件和错误

RxBus

活动

public class RxBus {

    private static final RxBus INSTANCE = new RxBus();

    private RxBus(){}
    private PublishSubject<Object> bus = PublishSubject.create();

    public static RxBus getInstance() {
        return INSTANCE;
    }


    public void send(Object o) {
        bus.onNext(o);
    }

    public void error(Throwable e){bus.onError(e);}

    public Observable<Object> toObservable() {
        return bus;
    }
}

在网络服务呼叫中

 FitnessRepo fitnessRepo = new FitnessRepo();
        fitnessRepo.getFitnessData();
        RxBus.getInstance().toObservable().subscribe(new Observer<Object>() {
            @Override
            public void onSubscribe(Disposable d) {

            }

            @Override
            public void onNext(Object o) {

                if(o instanceof RealmList ){

                    RealmList<Fitness> realmList = (RealmList<Fitness>) o;
                    Log.e(TAG,"Fitness data size "+realmList.size());

                }
            }

            @Override
            public void onError(Throwable e) {

                Log.e(TAG,e.getMessage()+ "");

                if (e instanceof HttpException) {
                    ResponseBody body = ((HttpException) e).response().errorBody();


                    try {

                        Response response=  LoganSquare.parse(body.byteStream(),Response.class);

                        if(response.getErrors() !=null)
                            if(response.getErrors().size() > 0)
                                Log.e(TAG, "Error "+response.getErrors().get(0).getErrors());
                    } catch (IOException t) {
                        t.printStackTrace();
                    }

                }
            }

            @Override
            public void onComplete() {

            }
        });

Answer 1

我对你有个好消息！您可以删除几乎所有代码，从而使其总体上更好！

public void fetchFitnessData() {

    Request request = new Request();
    request.setAccess_token("d80fa6bd6f78cc704104d61146c599bc94b82ca225349ee68762fc6c70d2dcf0");

    Flowable<Response> fitnessFlowable = new WebRequest()
                                        .getRemoteClient()
                                        .create(FitnessApi.class)
                                        .getFitnessData("5b238abb4d3590001d9b94a8",request.toMap());


     fitnessFlowable.subscribeOn(Schedulers.io())
            .takeUntil(response->response.getSummary().getNext()!=null)
            .doOnNext((response) -> {
                    if(response ==null || response.getFitness() == null || response.getFitness().isEmpty()) return;

                    try(Realm r = Realm.getDefaultInstance()) {
                        r.executeTransaction((realm) -> {
                            realm.insertOrUpdate(response.getFitness());
                        });
                    }
                }
            }).subscribe();
}

此方法现在在后台线程上并返回void，因此从该方法发出内容的方法是使用PublishSubject（一个用于成功，一个用于失败）或EventBus。

private PublishSubject<Object> fitnessResults;
public Observable<Object> observeFitnessResults() {
    return fitnessResults;
}

public static class Success {
    public Success(List<Fitness> data) {
        this.data = data;
    }

    public List<Fitness> data;
}

public static class Failure {
    public Failure(Exception exception) {
        this.exception = exception;
    }

    public Exception exception;
}

public void fetchFitnessData() {
    ...
        fitnessResults.onNext(new Success(data));
    } catch(Exception e) {
        fitnessResults.onNext(new Failure(e));

然后

errors = observeFitnessResults().ofType(Error.class);
success = observeFitnessResults().ofType(Success.class);

Answer 2

有多种方法可以实现此目的。我将永远不会在生命周期范围之外自行处理订阅，因为这可能会导致内存泄漏。在您的情况下，似乎成功与失败都与UI绑定在一起，因此您只需执行此操作即可。

public Completable fetchFitnessData() {

Request request = new Request();
request.setAccess_token("d80fa6bd6f78cc704104d61146c599bc94b82ca225349ee68762fc6c70d2dcf0");

Flowable<Response> fitnessFlowable = new WebRequest()
                                    .getRemoteClient()
                                    .create(FitnessApi.class)
                                    .getFitnessData("5b238abb4d3590001d9b94a8",request.toMap());


 return fitnessFlowable.subscribeOn(Schedulers.io())
        .takeUntil(response->response.getSummary().getNext()!=null)
        .doOnNext((response) -> {
                if(response ==null || response.getFitness() == null || response.getFitness().isEmpty()) return;

                try(Realm r = Realm.getDefaultInstance()) {
                    r.executeTransaction((realm) -> {
                        realm.insertOrUpdate(response.getFitness());
                    });
                }
            }
        }).ignoreElements();

}

在UI级别，您只能处理成功和失败的订阅。万一您需要成功模型，可以将Completable替换为Single或Flowable。

fetchFitnessData.subscrible(Functions.EMPTY_ACTION, Timber::d);

此方法的主要优点是您可以处理订阅生命周期。

从Web服务获取数据存储后，在RxJava中返回订户

2 个答案: