Stream - Collect by property and max

Question

Problem Statement

Given the following class (simplified for the question):

public static class Match {

  private final String type;
  private fina         


        

Answer 1

Try to use a TreeMap for this :

UPDATE

List matchStream1 = matchStream.
            collect(Collectors.groupingBy(Match::getType,
                    Collectors.toCollection(() -> new TreeSet<>(Comparator.comparing(Match::getScore)))))
            .values()
            .stream()
            .map(TreeSet::last)
            .collect(Collectors.toList());

In case your Match class implements Comparable. You can simplify this:

() -> new TreeSet<>(Comparator.comparing(Match::getScore))

to this:

TreeSet::new