RxExamples.java

package com.insightfullogic.java8.examples.chapter9;

import com.insightfullogic.java8.examples.chapter1.Artist;
import rx.Observable;
import rx.Observer;

import java.util.List;

import static java.util.stream.Collectors.toList;

public class RxExamples {

    private final List<Artist> savedArtists;
    private final List<String> savedArtistNames;

    public RxExamples(List<Artist> savedArtists) {
        this.savedArtists = savedArtists;
        savedArtistNames = savedArtists.stream()
                                       .map(Artist::getName)
                                       .collect(toList());
    }

    // BEGIN search
public Observable<Artist> search(String searchedName,
                                 String searchedNationality,
                                 int maxResults) {

    return getSavedArtists()  // <1>
          .filter(name -> name.contains(searchedName)) // <2>
          .flatMap(this::lookupArtist) // <3>
          .filter(artist -> artist.getNationality() // <4>
                                  .contains(searchedNationality))
          .take(maxResults); // <5>
}
    // END search

    //  ------------------ FAKE LOOKUP CODE ------------------
    //          Again, imaginary external web services

    private Observable<String> getSavedArtists() {
        return Observable.from(savedArtistNames);
    }

    private Observable<Artist> lookupArtist(String name) {
        Artist required = savedArtists.stream()
                                      .filter(artist -> artist.getName().equals(name))
                                      .findFirst()
                                      .get();

        return Observable.from(required);
    }

    // Purely for imported code sample
    public void creationCodeSample() {
        Observer<String> observer = null;

// BEGIN completing_observable
observer.onNext("a");
observer.onNext("b");
observer.onNext("c");
observer.onCompleted();
// END completing_observable

// BEGIN error_observable
observer.onError(new Exception());
// END error_observable

    }

}