Main.java - master - DevDenzo/StudentFileManager

Main.java
78 строк3 KB
Denis Sklyarskij
task done
13 дек 2025, 19:41
13 дек 2025, 19:4119403be
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.*;
import java.util.concurrent.atomic.AtomicInteger;

public class Main {
    public static void main(String[] args) {
        List < Student > students = new ArrayList < > ();

        try (FileInputStream fis = new FileInputStream("students.txt"); InputStreamReader isr = new InputStreamReader(fis, StandardCharsets.UTF_8); BufferedReader reader = new BufferedReader(isr)) {

            String line;
            while ((line = reader.readLine()) != null) {
                if (line.trim().isEmpty()) continue;

                String[] parts = line.split(",", 2);

                String name = parts[0].trim();
                String booksPart = parts[1];

                String[] bookStrings = booksPart.split(";");
                List < Book > bookList = new ArrayList < > ();

                for (String bookStr: bookStrings) {
                    String[] bookData = bookStr.split(",", 3);
                    if (bookData.length == 3) {
                        try {
                            Book book = new Book(
                                    bookData[0].trim(),
                                    Integer.parseInt(bookData[1].trim()),
                                    Integer.parseInt(bookData[2].trim())
                            );
                            bookList.add(book);
                        } catch (Exception e) {
                            System.err.println("Возникла ошибка при создании новой книги: " + bookStr);
                        }
                    } else {
                        System.err.println("Ожидался массив длиной 3, а получен: " + bookStr);
                    }
                }

                students.add(new Student(name, bookList));
            }

        } catch (IOException e) {
            System.err.println("Ошибка чтения файла: " + e.getMessage());
        }

        students
                .forEach(student -> {
                    AtomicInteger counter = new AtomicInteger(1);

                    System.out.println("Список книг студента: " + student.getName());

                    student.getBooks().stream()
                            .distinct()
                            .filter(book -> book.getYear() > 2000)
                            .sorted(Comparator.comparing(Book::getPages))
                            .limit(3)
                            .peek(book -> System.out.println(
                                    "[" + counter.getAndIncrement() + "] " +
                                            "Название: " + book.getTitle() +
                                            ", год: " + book.getYear() +
                                            ", страниц: " + book.getPages()
                            ))
                            /*.forEach(book -> {});*/
                            .map(Book::getYear)
                            .findFirst()
                            .ifPresentOrElse(
                                    year -> System.out.println("Результат Optional от года: " + year),
                                    () -> System.out.println("У студента отстутствуют книги напечатанные после 2000 года")
                            );
                });
    }
}