Java - Stream - Collect every N elements

Question

I am trying to learn java - stream. I am able to do simple iteration / filter / map / collection etc.

When I was kind of trying to collect every 3 elements and print

Answer 1

I solved it like this:

    List list = Arrays.asList("a","b","c","d","e","f","g","h","i","j");
    int groupBy = 3;

    AtomicInteger index = new AtomicInteger(0);         
    Map> groups = list.stream()
        .collect(Collectors.groupingBy(cdm -> index.getAndIncrement()/groupBy));

    System.out.println(groups);

It prepares a map where the line number is the key and the strings on the line are in the key.