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JavaRx parallelism
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package it.r.rx; | |
import org.apache.commons.lang.RandomStringUtils; | |
import rx.Observable; | |
import rx.functions.Action1; | |
import rx.schedulers.Schedulers; | |
import java.util.List; | |
import java.util.Random; | |
import java.util.stream.Collectors; | |
import java.util.stream.Stream; | |
public class Main { | |
public static void main(String[] args) { | |
final List<String> result = Observable.from(new Integer[]{4, 5, 6, 6, 7, 3}) | |
.doOnNext(debug("Init")) | |
.flatMap(i -> Observable.defer(() -> toRandomList(i)).subscribeOn(Schedulers.io())) | |
.doOnNext(debug("defer")) | |
.flatMap(Main::chooseString) | |
.doOnNext(debug("chooseString")) | |
.toList() | |
.doOnNext(debug("list")) | |
.toBlocking() | |
.single(); | |
System.out.println("\nresult = " + result); | |
} | |
public static Observable<List<String>> toRandomList(Integer n) { | |
debug("perform IO").call(n); | |
try { | |
Thread.sleep(new Random().nextInt(3000)); | |
} catch (InterruptedException e) { | |
e.printStackTrace(); | |
} | |
debug("IO done").call(n); | |
final List<String> result = Stream.iterate(0, t -> t + 1) | |
.map(i -> RandomStringUtils.randomAlphanumeric(n)) | |
.limit(n) | |
.collect(Collectors.toList()); | |
return Observable.just(result); | |
} | |
public static Observable<String> chooseString(List<String> list) { | |
if (Math.random() > .3) { | |
return Observable.just(list.get(new Random().nextInt(list.size()))); | |
} | |
else { | |
return Observable.empty(); | |
} | |
} | |
public static <T> Action1<T> debug(String s) { | |
return o -> System.out.println(o + " | " + s + " | " + Thread.currentThread().getName()); | |
} | |
} |
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