Instantiate List of objects with parameter array

Question

I would like to instantiate a List of objects using an Array of parameters like so:

String[] winnerData = ("Team_1#Team_2#...#Team_N").split("#");
List<Team> winners = new ArrayList();
for (String w : winnerData){
    winners.add(new Team(w));
}

How can I do this cleanly? Preferably in a single line.

I don't mind whether winners/winnerData is List or Array.

Answer 1

You can use the Stream API for such need.

String[] winnerData = ("Team_1#Team_2#...#Team_N").split("#");
// Create a Stream from the array of String
// For each String convert it as a Team using new Team(String)
// Convert the result as a List
List<Team> winners = Arrays.stream(winnerData)
    .map(Team::new)
    .collect(Collectors.toList());

Answer 2

You might want to consider skipping intermediate array creation using Pattern.splitAsStream:

// Declare the pattern somewhere in the appropriate class
static final Pattern DELIMITER = Pattern.compile("#");

String winnerData = "Team_1#Team_2#...#Team_N";
List<Team> winners = DELIMITER.splitAsStream(winnerData)
    .map(Team::new)
    .collect(Collectors.toList());

This way the intermediate array is not created making the whole chain completely lazy which may take less memory (and work faster) if you have many teams.