執行多個訂戶rxjava

Question

我有一個問題，使用rxJava。我需要兩次執行UseCase，但使用不同的參數並在每個變量中添加響應。問題是兩個變量在執行第二個UseCase之前有價值，但我不知道爲什麼。

回答在問題的端

例 執行第一GetCompanies - >departureTrip（具有值響應），但returnTrip具有值，而是在執行getCompaniesReturn

變量聲明

private GetCompanies getCompanies; 
private GetCompanies getCompaniesReturn; 
private SearchResponseDomain departureTrip; 
private SearchResponseDomain returnTrip; 

執行

getCompanies.execute(new CompaniesObserver()); 
getCompaniesReturn.execute(new CompaniesTravelDoubleObserver()); 

GetCompanies

public class GetCompanies extends UseCase { 

    private final AppRepository repository; 
    private String origin; 
    private String destination; 
    private String date; 
    private String passengers; 

    @Inject 
    public GetCompanies(AppRepository repository) { 
     this.repository = repository; 
    } 

    @Override 
    protected Observable buildObservableUseCase() { 
     return this.repository.getAllResultsSearch(origin, destination, date, passengers); 
    } 
} 

用例

public abstract class UseCase { 


    private Subscription subscription = Subscriptions.empty(); 

    protected UseCase() { 
    } 

    @SuppressWarnings("unchecked") 
    public void execute(Subscriber UseCaseSubscriber) { 
     this.subscription = this.buildObservableUseCase() 
       .observeOn(AndroidSchedulers.mainThread()) 
       .subscribeOn(Schedulers.io()) 
       .subscribe(UseCaseSubscriber); 
    } 

    /** 
    * Unsubscribes from current {@link rx.Subscription}. 
    */ 
    public void unsubscribe() { 
     if (!subscription.isUnsubscribed()) { 
      subscription.unsubscribe(); 
     } 
    } 

    protected abstract Observable buildObservableUseCase(); 
} 

代碼執行getCompanies個

private final class CompaniesObserver extends 
    DefaultSubscriber<SearchResponseDomain> { 
    @Override 
    public void onCompleted() { 
     combineResults(departureTrip,returnTrip); 
    } 

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

    @Override 
    public void onNext(SearchResponseDomain searchResponseDomain) { 
     super.onNext(searchResponseDomain); 
     departureTrip = searchMapper.reverseMap(searchResponseDomain); 
    } 
} 

代碼執行CompaniesTravelDoubleObserver

private final class CompaniesTravelDoubleObserver extends 
    DefaultSubscriber<SearchResponseDomain> { 
    @Override 
    public void onCompleted() { 
     super.onCompleted(); 
     combineResults(departureTrip,returnTrip); 
    } 

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

    @Override 
    public void onNext(SearchResponseDomain searchResponseDomain) { 
     super.onNext(searchResponseDomain); 
     returnTrip = searchMapper.reverseMap(searchResponseDomain); 
    } 
} 

方法驗證數據完成

public void combineResults(SearchResponsePresentation departureTrip,SearchResponsePresentation returnTrip){ 

     if(departureTrip != null && returnTrip != null){ 
      getView().hideLoading(); 
      getView().showCompanies(departureTrip,returnTrip); 
     } 
    } 

解

讀取後，並宣讀後和discutions，我發現幫助解決用戶@Hans沃斯特

1 - 我有一個問題，我沒有訪問的觀察到的，我需要在主持人訂閱

GetCompanies

public class GetCompanies //extends UseCase { 
{ 
    private final AppRepository repository; 
    private String origin; 
    private String destination; 
    private String date; 
    private String passengers; 

    @Inject 
    public GetCompanies(AppRepository repository) { 
     this.repository = repository; 
    } 

    //@Override 
    public Observable buildObservableUseCase() { 
     return this.repository.getAllResultsSearch(origin, destination, date, passengers); 
    } 


    public void setOrigin(String origin) { 
     this.origin = origin; 
    } 

    public void setDestination(String destination) { 
     this.destination = destination; 
    } 

    public void setDate(String date) { 
     this.date = date; 
    } 

    public void setPassengers(String passengers) { 
     this.passengers = passengers; 
    } 
} 

演示

Observable<SearchResponseDomain> departureTrip = getCompanies.buildObservableUseCase().subscribeOn(Schedulers.io()); 
      Observable<SearchResponseDomain> returnTrip  = getCompaniesReturn.buildObservableUseCase().subscribeOn(Schedulers.io()); 
      // Subs. to both observables. If one finishes -> whole stream closes 
      Observable<List<SearchResponseDomain>> zip = Observable.zip(departureTrip, returnTrip, (d, r) -> { 
       return Arrays.asList(d, r); 
      }); 
      // Subscribe 
      zip.observeOn(AndroidSchedulers.mainThread()) 
        .subscribe(new CompaniesTravelDoubleObserver()); 

    //------------------------------------------------------------// 
private final class CompaniesTravelDoubleObserver extends 
DefaultSubscriber<List<SearchResponseDomain>> { 
    @Override 
    public void onCompleted() { 
     getView().hideLoading(); 

    } 
    @Override 
    public void onError(Throwable e) { 
     getView().hideLoading(); 
     networkError.setError(e); 
     getView().hideLoading(); 
     getView().showError(networkError.getAppErrorMessage()); 
    } 

    @Override 
    public void onNext(List<SearchResponseDomain> searchResponseDomains) { 
     getView().showCompanies(searchMapper.reverseMap(searchResponseDomains)); 

    } 
} 

Answer 1

我會回答這個問題： *會有兩個不同的getCompany請求。如果兩個請求都處於（都返回一個值 - >單個），則結果必須顯示在UI中。

zip操作器將來自一個流的每個值與來自另一個流的值相結合。

請注意，在大多數情況下，應該對操作員構成可觀察的結果，並且應該有很少的地方，您訂閱的地方。

@Test 
public void name() throws Exception { 
    Observable<SearchResponseDomain> departureTrip = getCompanies(); 
    Observable<SearchResponseDomain> returnTrip = getCompanies(); 

    // Subs. to both observables. If one finishes -> whole stream closes 
    Observable<List<SearchResponseDomain>> zip = Observable.zip(departureTrip, returnTrip, (d, r) -> { 
     return Arrays.asList(d, r); 
    }); 

    // Subscribe 
    zip.observeOn(AndroidSchedulers.mainThread()) 
      .subscribe(searchResponseDomain -> { 
       // show stuff in UI 
      }); 

} 

// TODO: add params to getCompanies... 
private Observable<SearchResponseDomain> getCompanies() { 
    return Observable.just(new SearchResponseDomain()); 
} 

class SearchResponseDomain { 

} 

我希望我從上面的代碼中獲得了你的意圖。如果你想有一個乾淨的用戶界面體驗，請看看傑克沃頓的演示文稿：https://speakerdeck.com/jakewharton/the-state-of-managing-state-with-rxjava-devoxx-us-2017