Rxjava2 + Retrofit2 + Android。 进行数百次网络通话的最佳方式

Question

我有一个应用程序。 我有一个大按钮，允许用户一次将所有数据同步到云端。 重新同步功能，允许他们再次发送所有数据。 （300多个条目）

我正在使用RXjava2和retrofit2。 我的单元测试只需一次通话即可完成。 但是我需要进行N次网络呼叫。

我想避免的是让observable调用队列中的下一个项目。 我正处于需要实现runnable的地步。 我已经看过一些关于地图但我没有看到有人将它用作队列。 此外，我想避免让一个项目失败并报告所有项目失败，就像Zip功能一样。 我应该只是做一个跟踪队列的令人讨厌的经理类吗？ 或者有更清洁的方式发送数百件物品？

注意：解决方案不能依赖于JAVA8 / LAMBDAS。 事实证明，这比合理的工作要多得多。

请注意，所有项目都是同一个对象。

    @Test
public void test_Upload() {
    TestSubscriber<Record> testSubscriber = new TestSubscriber<>();
    ClientSecureDataToolKit clientSecureDataToolKit = ClientSecureDataToolKit.getClientSecureDataKit();
    clientSecureDataToolKit.putUserDataToSDK(mPayloadSecureDataToolKit).subscribe(testSubscriber);

    testSubscriber.awaitTerminalEvent();
    testSubscriber.assertNoErrors();
    testSubscriber.assertValueCount(1);
    testSubscriber.assertCompleted();
}

我的帮手收集并发送我的所有物品

public class SecureDataToolKitHelper {
private final static String TAG = "SecureDataToolKitHelper";
private final static SimpleDateFormat timeStampSimpleDateFormat =
        new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");


public static void uploadAll(Context context, RuntimeExceptionDao<EventModel, UUID> eventDao) {
    List<EventModel> eventModels = eventDao.queryForAll();

    QueryBuilder<EventModel, UUID> eventsQuery = eventDao.queryBuilder();
    String[] columns = {...};

    eventsQuery.selectColumns(columns);

    try {
        List<EventModel> models;

        models = eventsQuery.orderBy("timeStamp", false).query();
        if (models == null || models.size() == 0) {
            return;
        }

        ArrayList<PayloadSecureDataToolKit> toSendList = new ArrayList<>();
        for (EventModel eventModel : models) {
            try {
                PayloadSecureDataToolKit payloadSecureDataToolKit = new PayloadSecureDataToolKit();

                if (eventModel != null) {


                  // map my items ... not shown

                    toSendList.add(payloadSecureDataToolKit);
                }
            } catch (Exception e) {
                Log.e(TAG, "Error adding payload! " + e + " ..... Skipping entry");
            }
        }

        doAllNetworkCalls(toSendList);

    } catch (SQLException e) {
        e.printStackTrace();
    }

}

我的改造之物

public class ClientSecureDataToolKit {

    private static ClientSecureDataToolKit mClientSecureDataToolKit;
    private static Retrofit mRetrofit;

    private ClientSecureDataToolKit(){
        mRetrofit = new Retrofit.Builder()
        .baseUrl(Utilities.getSecureDataToolkitURL())
        .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
        .addConverterFactory(GsonConverterFactory.create())
        .build();
    }

    public static ClientSecureDataToolKit getClientSecureDataKit(){
        if(mClientSecureDataToolKit == null){
            mClientSecureDataToolKit = new ClientSecureDataToolKit();
        }
        return mClientSecureDataToolKit;
    }

    public Observable<Record> putUserDataToSDK(PayloadSecureDataToolKit payloadSecureDataToolKit){
        InterfaceSecureDataToolKit interfaceSecureDataToolKit = mRetrofit.create(InterfaceSecureDataToolKit.class);
        Observable<Record> observable = interfaceSecureDataToolKit.putRecord(NetworkUtils.SECURE_DATA_TOOL_KIT_AUTH, payloadSecureDataToolKit);
        return observable;
    }

}

public interface InterfaceSecureDataToolKit {

@Headers({
        "Content-Type: application/json"
})

@POST("/api/create")
Observable<Record> putRecord(@Query("api_token") String api_token, @Body PayloadSecureDataToolKit payloadSecureDataToolKit);
 }

---

更新。 我一直试图将这个答案应用于运气不多。 我今晚正在失去动力。 我试图将其作为一个单元测试实现，就像我为一个项目的原始调用所做的那样。看起来像使用lambda的东西是不对的...

public class RxJavaBatchTest {
    Context context;
    final static List<EventModel> models = new ArrayList<>();

    @Before
    public void before() throws Exception {
        context = new MockContext();
        EventModel eventModel = new EventModel();
        //manually set all my eventmodel data here.. not shown 

        eventModel.setSampleId("SAMPLE0");
        models.add(eventModel);
        eventModel.setSampleId("SAMPLE1");
        models.add(eventModel);
        eventModel.setSampleId("SAMPLE3");
        models.add(eventModel);


    }

    @Test
    public void testSetupData() {
        Assert.assertEquals(3, models.size());
    }

    @Test
    public void testBatchSDK_Upload() {


        Callable<List<EventModel> > callable = new Callable<List<EventModel> >() {

            @Override
            public List<EventModel> call() throws Exception {
                return models;
            }
        };

        Observable.fromCallable(callable)
                .flatMapIterable(models -> models)
                .flatMap(eventModel -> {
                    PayloadSecureDataToolKit payloadSecureDataToolKit = new PayloadSecureDataToolKit(eventModel);
                    return doNetworkCall(payloadSecureDataToolKit) // I assume this is just my normal network call.. I am getting incompatibility errors when I apply a testsubscriber...
                            .subscribeOn(Schedulers.io());
                }, true, 1);
    }

    private Observable<Record> doNetworkCall(PayloadSecureDataToolKit payloadSecureDataToolKit) {

        ClientSecureDataToolKit clientSecureDataToolKit = ClientSecureDataToolKit.getClientSecureDataKit();
        Observable observable = clientSecureDataToolKit.putUserDataToSDK(payloadSecureDataToolKit);//.subscribe((Observer<? super Record>) testSubscriber);
        return observable;
    }

结果是......

An exception has occurred in the compiler (1.8.0_112-release). Please file a bug against the Java compiler via the Java bug reporting page (http://bugreport.java.com) after checking the Bug Database (http://bugs.java.com) for duplicates. Include your program and the following diagnostic in your report. Thank you.
com.sun.tools.javac.code.Symbol$CompletionFailure: class file for java.lang.invoke.MethodType not found


FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:compile<MyBuildFlavorhere>UnitTestJavaWithJavac'.
> Compilation failed; see the compiler error output for details.

---

编辑。 不再尝试Lambdas。 即使在我的mac上设置路径后，javahome也指向1.8等等。我无法让它工作。 如果这是一个较新的项目，我会更加努力。 然而，由于这是一个由尝试android的Web开发人员编写的继承的android应用程序，它不是一个很好的选择。 也不值得花时间让它发挥作用。 已经进入这个任务的日子而不是半天它应该采取。

我找不到一个好的非lambda flatmap示例。 我自己尝试了，它变得很乱。

Answer 1

如果我理解正确，你想并行打电话吗？

所以rx-y的做法是这样的：

    Observable.fromCallable(() -> eventsQuery.orderBy("timeStamp", false).query())
            .flatMapIterable(models -> models)
            .flatMap(model -> {
                // map your model

                //avoid throwing exceptions in a chain, just return Observable.error(e) if you really need to
                //try to wrap your methods that throw exceptions in an Observable via Observable.fromCallable()


                return doNetworkCall(someParameter)
                        .subscribeOn(Schedulers.io());
            }, true /*because you don't want to terminate a stream if error occurs*/, maxConcurrent /* specify number of concurrent calls, typically available processors + 1 */)
            .subscribe(result -> {/* handle result */}, error -> {/* handle error */});

在ClientSecureDataToolKit将此部分移动到构造函数中

    InterfaceSecureDataToolKit interfaceSecureDataToolKit = mRetrofit.create(InterfaceSecureDataToolKit.class);