我的当前Android应用程序采用Retrofit
和RxJava
来协调我的网络调用。
我将我的HTTP GET模拟为Single<Response<String>>
,POST模拟为Completable
。
我需要的调用顺序如下:
按顺序调用GET(1)、GET(2)、GET(3)
并行调用POST(1)、POST(2)
当POST(1)和POST(2)都完成时,调用GET(4)。
我有一个部分解决方案。我已经编码了前三个GET的调用,然后是POST调用。
我的代码类似于:
// First we make the 3 GET calls sequentially
Single> call1 = apiService.getData1();
Single> call2 = apiService.getData2();
Single> call3 = apiService.getData3();
// Once they are all done, then fire off the 2 POSTs in parallel
Completable.mergeArray(apiService.postData1(), apiService.postData2())
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(() -> {
// *** Here is where I need to add the final GET ***
});
Single.concat(getRequests())
.subscribeOn(Schedulers.single())
.doOnError(throwable -> Log.e(TAG, "Manage Totals Failed", throwable))
.doFinally(new Action() {
@Override
public void run() throws Exception {
manageExecutions(combineExecutions());
}
})
.subscribe();
/**
* @return
*/
private static Iterable<Single<Response<String>>> getRequests() {
final API_CALL_GET[] apiCalls = API_CALL_GET.values();
final List<Single<Response<String>>> requests = new ArrayList<>(apiCalls.length);
for (final API_CALL_GET apiCall : apiCalls) {
requests.add(apiCall.request());
}
return requests;
}
public enum API_CALL_GET {
GET_ONE {
@Override
public Single<Response<String>> request() {
return RETRO_SERVICE
.getOne(authToken, new HashMap<>())
.doAfterSuccess(this::persistDataOne)
.doOnError(error -> ever(error));
}
}, GET_TWO {
@Override
public Single<Response<String>> request() {
return RETRO_SERVICE
.getTwo(authToken, new HashMap<>())
.doAfterSuccess(this::persistDataTwo)
.doOnError(error -> ever(error));
}
},
GET_THREE {
@Override
public Single<Response<String>> request() {
return RETRO_SERVICE
.getThree(authToken, new HashMap<>())
.doAfterSuccess(this::persistDataThree)
.doOnError(error -> ever(error));
}
};
public abstract Single<Response<String>> request();
}
private static Action manageExecutions(final List<Completable> completables) {
return new Action() {
@Override
public void run() throws Exception {
Completable
.concat(completables)
.subscribeOn(Schedulers.io())
.doOnError(throwable -> Log.e(TAG, "Manage Totals Failed", throwable))
.doOnComplete(new Action() {
@Override
public void run() throws Exception {
accumulateAmounts();
}
})
.subscribe();
}
};
}
/**
* @return
*/
private static List<Completable> combineExecutions() {
final API_CALL_POST[] apiCalls = API_CALL_POST.values();
final List<Completable> requests = new ArrayList<>(apiCalls.length);
for (final API_CALL_POST apiCall : apiCalls) {
requests.addAll(apiCall.requests());
}
return Lists.newArrayList(Iterables.unmodifiableIterable(requests));
}
public enum API_CALL_POST {
POST_ONE {
@Override
public List<Completable> requests() {
return NetworkController.postRecommenderExecutions();
}
},
POST_TWO {
@Override
public List<Completable> requests() {
return NetworkController.postSavedSearcheExecutions();
}
};
public abstract List<Completable> requests();
}
public static List<Completable> postONE() {
final List<Completable> completables = new ArrayList<>();
final List<OneDO> oneDOS = fetchOnes();
for (final OneDO oneDO : oneDOS) {
completables.add(RETRO_SERVICE.runCompletableOnes(authToken, oneDO.getId())
.doOnError(new Consumer<Throwable>() {
@Override
public void accept(final Throwable throwable) throws Exception {
Log.e(TAG, "accept: ", throwable);
}
}));
}
return completables;
}
public static List<Completable> postTWO() {
final List<Completable> completables = new ArrayList<>();
final List<TwoDO> twoDOS = fetchTwos();
for (final TwoDO twoDO : twoDOS) {
completables.add(RETRO_SERVICE.runCompletableTwos(authToken, twoDO.getId())
.doOnError(new Consumer<Throwable>() {
@Override
public void accept(final Throwable throwable) throws Exception {
Log.e(TAG, "accept: ", throwable);
}
}));
}
return completables;
}
我遇到困难的是正确地连接我的调用,例如,我认为我可以开发出类似于这个伪代码的解决方案:Single.concat(GET_1... GET_N).onComplete(POST_1... POST_N).onComplete(GET_LAST)。然而,我的目前的部分解决方案只调用第一组GET,然后是POST,而且GET和POST的调用没有"链式"链接。我无法看出如何创建支持我的用例的调用链。是否可以在链式调用中结合 Single -> Completable -> Single?基于Daniil的回答,我最终得到了这个解决方案:- Single.concat(getRequests())
.subscribeOn(Schedulers.io())
.doOnError(throwable -> Log.e(TAG, "accept[0000]: ", throwable))
.ignoreElements()
.andThen(Completable.merge(combineExecutions()))
.doOnError(throwable -> Log.e(TAG, "accept: ", throwable))
.doOnComplete(() -> Controller.accumulateTotals())
.subscribe();