RxJava1到Rxjava2遷移錯誤

Question

轉換RxJava1代碼RXJava2給予這個錯誤，不知道我做錯了

無類型變量（一個或多個）R的實例（S）存在，使得單>符合ObserableSource

API調用

@GET("/search/users?per_page=2") 
Observable<UsersList> searchGithubUsers(@Query("q") String searchTerm); 

@GET("https://stackoverflow.com/users/{username}") 
Observable<User> getUser(@Path("username") String username); 

RxJAva1：

public Observable<List<User>> searchUsers(final String searchTerm) { 
     return Observable.defer(() -> githubUserRestService.searchGithubUsers(searchTerm).concatMap(
       usersList -> Observable.from(usersList.getItems()) 
         .concatMap(user -> githubUserRestService.getUser(user.getLogin())).toList())) 
       .retryWhen(observable -> observable.flatMap(o -> { 
        if (o instanceof IOException) { 
         return Observable.just(null); 
        } 
        return Observable.error(o); 
       })); 
    } 

RXJava2

public Observable<List<User>> searchUsers(final String searchTerm) { 
     return Observable.defer(() -> githubUserRestService.searchGithubUsers(searchTerm).concatMap(
       usersList -> Observable.fromIterable(usersList.getItems()) 
         .concatMap(user -> githubUserRestService.getUser(user.getLogin())).toList())) 
       .retryWhen(observable -> observable.flatMap(o -> { 
        if (o instanceof IOException) { 
         return Observable.just(null); 
        } 
        return Observable.error(o); 
       })); 
    } 

Answer 1

toList回報Single在2.X;之後你必須申請toObservable()。還要注意的是Observable.just(null)禁止：空一般不允許與RxJava 2.

Observable<List<User>> searchUsers(final String searchTerm) { 
    return Observable.defer(() -> 
     githubUserRestService 
      .searchGithubUsers(searchTerm) 
      .concatMap(usersList -> 
       Observable.fromIterable(usersList.getItems()) 
        .concatMap(user -> 
         githubUserRestService 
         .getUser(user.getLogin())) 
         .toList() 
         .toObservable() 
        ) 
      ) 
      .retryWhen(observable -> 
       observable.flatMap(o -> { 
        if (o instanceof IOException) { 
         return Observable.just(0); 
        } 
        return Observable.error(o); 
       }) 
      ) 
     ); 
}