Friendlist Maintenance

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;

public class FriendListMaintenance {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        String[] names = scanner.nextLine().split(", ");
        ArrayList<String> friends = new ArrayList<>(Arrays.asList(names));
        int blacklistCount = 0;
        int lostNamesCount = 0;


        String command = scanner.nextLine();
        while (!"Report".equals(command)) {
            String[] tokens = command.split(" ");
            String type = tokens[0];

            switch (type) {
                case "Blacklist": {
                    String name = tokens[1];
                    if (friends.contains(name)) {
                        int indexName = friends.indexOf(name);
                        friends.set(indexName, "Blacklisted");
                        System.out.println(String.format("%s was blacklisted.", name));
                        blacklistCount++;
                    } else {
                        System.out.println(String.format("%s was not found.", name));
                    }
                    break;
                }
                case "Error": {
                    int index = Integer.parseInt(tokens[1]);
                    String currName = friends.get(index);
                    if (!currName.equals("Blacklisted") && !currName.equals("Lost")) {
                        friends.set(index, "Lost");
                        lostNamesCount++;
                        System.out.println(String.format("%s was lost due to an error.", currName));
                    }
                    break;
                }
                case "Change": {
                    int index = Integer.parseInt(tokens[1]);
                    String newName = tokens[2];
                    if (isValidIndex(friends, index)) {
                        String currName = friends.get(index);
                        friends.set(index, newName);
                        System.out.println(String.format("%s changed his username to %s."
                                , currName, newName));
                    }
                    break;
                }
            }

            command = scanner.nextLine();
        }
        System.out.println(String.format("Blacklisted names: %d", blacklistCount));
        System.out.println(String.format("Lost names: %d", lostNamesCount));
        for (String friend : friends) {
            System.out.print(friend + " ");
        }

    }

    private static boolean isValidIndex(ArrayList<String> friends, int index) {
        return 0 <= index && index < friends.size();
    }
}