CODEWITHSUNDEEP
rx-java
Tura
Tura

Reputation: 1326

RxJava Transforming Map into List

Here's desired behavior:

[A: 4, B: 2, C: 3, D: 3] -> [A,A,A,A,B,B,C,C,C,D,D,D]

I wrote some code to tackle this.. Here's the code:

Map<String, Integer> terms = new HashMap<>();
Stream.of(terms.entrySet())
    .flatMap(entry -> {
        List<String> items = new ArrayList<>();
        for (int i = 0; i < entry.getValue(); i++) {
            items.add(entry.getKey());
        }
        return Stream.of(items);
    })
    .forEach(System.out::println);

Is there a better way to do this? I'm relatively new to Rx, so I want to know if there's a best practice or something like that.

Upvotes: 0

Views: 227

Answers (1)

Niraj Chauhan
Niraj Chauhan

Reputation: 7880

How about this:

terms.keySet().stream()
    .map(s -> IntStream.range(0, map.get(s))
            .mapToObj(i -> s).collect(Collectors.toList()))
    .flatMap(List::stream)
    .collect(Collectors.toList());

Upvotes: 2

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