Books collection

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

class Book implements Comparable<Book>{
    private String title;
    private String category;
    private float price;

    public float getPrice() {
        return price;
    }

    public String getBookCategory() {
        return category;
    }

    Book(String title, String category, float price){
        this.title = title;
        this.category = category;
        this.price = price;
    }

    @Override
    public int compareTo( Book o) {
            if (this.title.toLowerCase().equals(o.title.toLowerCase() )){
                return Float.compare(this.price,o.price);
            }
            else{
                return this.title.toLowerCase().compareTo(o.title.toLowerCase());
            }
    }

    @Override
    public String toString() {
        return String.format("%s (%s) %.2f",title,category,price);
    }
}

class BookCollection{

    List<Book> bookCollection;

    public BookCollection() {
        bookCollection = new LinkedList<>();
    }

    public void addBook(Book book){
        bookCollection.add(book);
    }
    public void printByCategory(String category){
        List<Book> copyCollection = bookCollection.stream()
                .filter(x -> x.getBookCategory().equals(category))
                .sorted().collect(Collectors.toList());

        copyCollection.forEach(System.out::println);

    }
    public List<Book> getCheapestN(int n){

        Comparator<Book> comparator = Comparator.comparing(Book::getPrice);

        return bookCollection.stream()
                .sorted()
                .sorted(comparator)
                .limit(n)
                .collect(Collectors.toList());

    }
}



public class BooksTest {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        scanner.nextLine();
        BookCollection booksCollection = new BookCollection();
        Set<String> categories = fillCollection(scanner, booksCollection);
        System.out.println("=== PRINT BY CATEGORY ===");
        for (String category : categories) {
            System.out.println("CATEGORY: " + category);
            booksCollection.printByCategory(category);
        }
        System.out.println("=== TOP N BY PRICE ===");
        print(booksCollection.getCheapestN(n));
    }

    static void print(List<Book> books) {
        for (Book book : books) {
            System.out.println(book);
        }
    }

    static TreeSet<String> fillCollection(Scanner scanner,
                                          BookCollection collection) {
        TreeSet<String> categories = new TreeSet<String>();
        while (scanner.hasNext()) {
            String line = scanner.nextLine();
            String[] parts = line.split(":");
            Book book = new Book(parts[0], parts[1], Float.parseFloat(parts[2]));
            collection.addBook(book);
            categories.add(parts[1]);
        }
        return categories;
    }
}

// Вашиот код овде