stream_api/task4/Main.java - master - konick_gs/netology-lambda

stream_api/task4/Main.java
53 строки2 KB
gilsar
Задача 4: Перепись населения
04 июл 2026, 19:01
04 июл 2026, 19:01eb9ce39
package stream_api.task4;

import java.util.*;
import java.util.stream.Collectors;

public class Main {

    public static void main(String[] args) {
        Collection<Person> persons = generatePersons();

        long childrenCount = persons.stream()
                .filter(person -> person.getAge() < 18)
                .count();

        System.out.println("Количество несовершеннолетних: " + childrenCount);

        var recruitsList = persons.stream()
                .filter(person -> person.getAge() >= 18 && person.getAge() <= 27)
                .filter(person -> person.getSex() == Sex.MAN)
                .map(person -> person.getFamily())
                .collect(Collectors.toList());

        System.out.println("Количество призывников: " + recruitsList.size());

        var highEducationList = persons.stream()
                .filter(person -> person.getEducation() == Education.HIGHER)
                .filter(person -> person.getAge() >= 18)
                .filter(person -> person.getSex() == Sex.MAN ?
                        person.getAge() < 65 : person.getAge() < 60)
                .sorted(Comparator.comparing(Person::getFamily))
                .collect(Collectors.toList());

        System.out.println("Количество работоспособных людей с высшим образованием: " + highEducationList.size());
    }

    public static Collection<Person> generatePersons() {

        List<String> names = Arrays.asList("Jack", "Connor", "Harry", "George", "Samuel", "John");
        List<String> families = Arrays.asList("Evans", "Young", "Harris", "Wilson", "Davies", "Adamson", "Brown");
        Collection<Person> persons = new ArrayList<>();
        for (int i = 0; i < 10_000_000; i++) {
            persons.add(new Person(
                    names.get(new Random().nextInt(names.size())),
                    families.get(new Random().nextInt(families.size())),
                    new Random().nextInt(100),
                    Sex.values()[new Random().nextInt(Sex.values().length)],
                    Education.values()[new Random().nextInt(Education.values().length)])
            );
        }

        return persons;
    }
}