{}
import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import java.util.stream.Collectors;
class Main
{
public static void main(String[] args)
{
List<User> users = Arrays.asList(
new User("Alice", 30, true),
new User("Bob", 25, false),
new User("Charlie", 35, true),
new User("Diana", 28, true),
new User("Eve", 22, false)
);
List<User> active = users.stream()
.filter(u -> u.active)
.sorted(Comparator.comparing(u -> u.name))
.collect(Collectors.toList());
System.out.println(active.stream()
.map(u -> u.name)
.collect(Collectors.joining(", ")));
double avg = active.stream()
.mapToInt(u -> u.age)
.average()
.orElse(0);
System.out.printf("Průměrný věk: %.1f%n", avg);
}
}
class User
{
String name;
int age;
boolean active;
User(String name, int age, boolean active)
{
this.name = name;
this.age = age;
this.active = active;
}
}