Collectors Map about lightweight-stream-api HOT 2 CLOSED

 Integer partitionItem = 1;
        List<Integer> items = Arrays.asList(1, 2, 3, 1, 2, 3, 1, 2, 3);

        Map<Boolean, List<Integer>> groupedBy = items.stream()
                .collect(Collectors.groupingBy(i -> i.equals(partitionItem)));

        items = new ArrayList<>(groupedBy.get(true));
        items.addAll(groupedBy.get(false));
        System.out.println(ones);