CODEWITHSUNDEEP
javajava-8java-stream
MrFisherman
MrFisherman

Reputation: 738

How to collect custom class object from stream in Java 8?

I have a Map<Flashcard, FlashcardStats> flashcards. The Flashcard class contains two fields: String term and String definition. When I have to find specific flashcard from flashcards, how can I do it via Java 8 Streams? How can I collect Flashcard object or just definition field having only term?

For example:

private static String getWrongAnswerMessage(Map<Flashcard, FlashcardStats> flashcards, String term, String answer) {

Flashcard flashcard = flashcards.keySet().stream().filter(o -> o.getTerm().equals(term)).collect() //what now

Upvotes: 3

Views: 1685

Answers (1)

vishnu
vishnu

Reputation: 2011

Assuming on one maching result

Optional<String> term = flashcards.keySet()
                  .stream()
                  .filter(o->o.getTerm().equals(term))
                  .map(Flashcard::getTerm)
                  .findFirst();

Upvotes: 5

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