在Android中使用RX2使用NetworkOnMainThreadException

Question

在这里研究Rx实现。

我的问题：可以在这里运行此代码而无需任何异步/可运行吗？据我了解，RX为自己创造了新线程。它可以使运行吗？此代码返回NetworkonMainThreadException

类Testinternet

public class TestInternet implements SOService.TestInternet {
    //TIMEOUT EN MILISEGUNDOS
    private final int MILISECONDS = 3000;
    @Override
    //returns the observable with connection/no connection
    public Observable <Boolean> getObservableConnection(String filter) {

            Observable<Boolean> networkAvalaible;
            try {
                    URL myUrl = new URL("http://flickr.com");
                    URLConnection connection = myUrl.openConnection();
                    connection.setConnectTimeout(MILISECONDS);
                    connection.connect();
                    networkAvalaible = Observable.just(true);
            } catch (Exception e) {
                    //I'm catching NetworkInMainThreadException here
                    e.printStackTrace();
                    networkAvalaible = Observable.just(false);
                    Log.d("error en testinternet",e.toString());
            }

            return networkAvalaible.subscribeOn(Schedulers.newThread())
                    .observeOn(AndroidSchedulers.mainThread());
    }

来自介绍者java

testInternet.getObservableConnection(filtro).subscribeWith(getConnectionObserver());


//comprueba conexión
public DisposableObserver<Boolean> getConnectionObserver() {
    return new DisposableObserver<Boolean>() {
        @Override                //envia los datos al recyclerview
        public void onNext(@NonNull Boolean aBoolean) {
            Log.d("rx","CONNECTION HAY NEXT");
            //envia los datos al recyclerview
            if (!aBoolean){
                Log.d("connnexcion", aBoolean.toString());
                mainView.showError(mainView.getContext().getText(R.string.no_connected).toString());
            }else if (aBoolean){
                Log.d("connnexcion", "on next correcto");
                mainView.hideError();
            }
        }

Answer 1

您有此例外，因为您在此行中对Android Mainthread进行网络电话： URLConnection connection = myUrl.openConnection();RX处理多线程由Schedulers(代码中的subscribeOn(Schedulers.newThread())(。但是您在Observable外进行网络呼叫将您的电话包装在Observable中，它将起作用

您的编辑代码

public class TestInternet implements SOService.TestInternet {
    //TIMEOUT EN MILISEGUNDOS
    private final int MILISECONDS = 3000;
    @Override
    //returns the observable with connection/no connection
    public Observable <Boolean> getObservableConnection(String filter) {  
        return Observable.create(new ObservableOnSubscribe<Boolean>() {
            @Override
            public void subscribe(ObservableEmitter<Boolean> emitter) throws Exception {
                try {
                    URL myUrl = new URL("http://flickr.com");
                    URLConnection connection = myUrl.openConnection();
                    connection.setConnectTimeout(MILISECONDS);
                    connection.connect();
                    emitter.onNext(true);
                } catch (Exception e) {
                    //I'm catching NetworkInMainThreadException here
                    e.printStackTrace();
                    emitter.onNext(false);
                    Log.d("error en testinternet", e.toString());
                }
            }
        })
                .subscribeOn(Schedulers.newThread())
                .observeOn(AndroidSchedulers.mainThread()); 
    }