在这片文章里，主要介绍怎么用Java 8 Stream的开源框架 来解答上一些经常被问到关于Java 8 Stream的问题：

用JDK Stream API:

Map
    
      result =    choices.stream().collect(Collectors.toMap(Choice::getName,                                              Function.identity()));
    

用StreamEx API：

Map
    
      result = StreamEx.of(choices).toMap(Choice::getName);
    

用JDK Stream API:

ForkJoinPool forkJoinPool = new ForkJoinPool(2);forkJoinPool.submit(() ->    //parallel task here, for example    IntStream.range(1, 1_000_000).parallel().filter(PrimesPrint::isPrime).collect(toList())).get();

用StreamEx API：

IntStreamEx.range(1, 1_000_000).parallel(new ForkJoinPool(2))           .filter(PrimesPrint::isPrime).toList();

用JDK Stream API:

public static 
    
      Predicate
     
       distinctByKey(Function
       keyExtractor) {    Set
      
     
    

用StreamEx API：

StreamEx.of(persons).distinctBy(Person::getName);

用JDK Stream API:

Stream.of(objects)    .filter(Client.class::isInstance)    .map(Client.class::cast)    .map(Client::getID)    .forEach(System.out::println);

用StreamEx API：

StreamEx.of(objects)    .select(Client.class)    .map(Client::getID)    .forEach(System.out::println);