Shuffle a list of integers with Java 8 Streams API

Question

I tried to translate the following line of Scala to Java 8 using the Streams API:

// Scala util.Random.shuffle((1 to 24).toList) 

To write the equivalent in Java I created a range of integers:

IntStream.range(1, 25) 

I suspected to find a toList method in the stream API, but IntStream only knows the strange method:

collect(   Supplier<R> supplier, ObjIntConsumer<R> accumulator, BiConsumer<R,R> combiner) 

How can I shuffle a list with Java 8 Streams API?

Answer 1

Here you go:

List<Integer> integers =     IntStream.range(1, 10)                      // <-- creates a stream of ints         .boxed()                                // <-- converts them to Integers         .collect(Collectors.toList());          // <-- collects the values to a list  Collections.shuffle(integers);  System.out.println(integers); 

Prints:

[8, 1, 5, 3, 4, 2, 6, 9, 7]