[NP] Event Calendar

import java.util.Scanner;
import java.util.stream.Collectors;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Scanner;
import java.util.Comparator;
import java.util.*;
public class EventCalendarTest {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        scanner.nextLine();
        int year = scanner.nextInt();
        scanner.nextLine();
        EventCalendar eventCalendar = new EventCalendar(year);
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd.MM.yyyy HH:mm");

        for (int i = 0; i < n; ++i) {
            String line = scanner.nextLine();
            String[] parts = line.split(";");
            String name = parts[0];
            String location = parts[1];
            LocalDateTime date = LocalDateTime.parse(parts[2], formatter);
            try {
                eventCalendar.addEvent(name, location, date);
            } catch (WrongDateException e) {
                System.out.println(e.getMessage());
            }
        }

        LocalDateTime date = LocalDateTime.parse(scanner.nextLine(), formatter);
        eventCalendar.listEvents(date);
        eventCalendar.listByMonth();
    }
}

class WrongDateException extends Exception{
    public WrongDateException(LocalDateTime date) {
        super(String.format("Wrong date: %s",date));
    }
}


class EventCalendar {
    List<Event> events;
    int year;

    public EventCalendar(int year) {
        events = new ArrayList<>();
        this.year=year;
    }

    public void addEvent(String name, String location, LocalDateTime date) throws WrongDateException {
        if(date.getYear()!=year)
            throw new WrongDateException(date);
        events.add(new Event(name,location,date));
    }

    public void listEvents(LocalDateTime date) {
        events.stream().sorted().filter(i->i.getDate().getDayOfYear()==date.getDayOfYear())
                .forEach(System.out::println);
    }

    public void listByMonth() {
        Map<Integer,Long> eventsByMonth = events.stream().collect(Collectors.groupingBy(
                Event::getMonth,
                TreeMap::new,
                Collectors.counting()
        ));
        for(int i=1;i<=12;i++){
            eventsByMonth.putIfAbsent(i,0L);
        }

        for(Integer i : eventsByMonth.keySet()){
            System.out.println(String.format("%d : %d",i,eventsByMonth.get(i)));
        }
    }
}


class Event implements Comparable<Event>{
    String name;
    String location;
    LocalDateTime date;

    public Event(String name, String location, LocalDateTime date) {
        this.name = name;
        this.location = location;
        this.date = date;
    }

    public String getName() {
        return name;
    }

    public String getLocation() {
        return location;
    }

    public LocalDateTime getDate() {
        return date;
    }

    public int getMonth(){
        return getDate().getMonth().getValue();
    }
    public String getThreeChars(String month){
        return month.substring(0,1)+month.substring(1,3).toLowerCase();
    }

    @Override
    public String toString() {
        return String.format("%d %s, %d %02d:%02d at %s, %s",getDate().getDayOfMonth(),getThreeChars(getDate().getMonth().toString()),
                getDate().getYear(),getDate().getHour(),getDate().getMinute(),getLocation(),getName());
    }

    @Override
    public int compareTo(Event o) {
        return Comparator.comparing(Event::getDate)
                .thenComparing(Event::getName)
                .compare(this,o);
    }
}