Surprise Test Post

import java.util.*;
import java.lang.Thread;

public class Book {
    public int id;
    public static int newID = 0;
    public String title;
    public int pages;
    public long time;
    public long expirationTime;
    public int stampRenews;

    public Book(String titleInput, int pageInput) {
        title = titleInput;
        pages = pageInput;
        id = newID;
        time = System.currentTimeMillis();
        expirationTime = 5000;
        newID++;
    }

    public String getTitle() {
        return title;
    }

    public int getPage() {
        return pages;
    }

    public int getID() {
        return id;
    }

    public long getTime() {
        return time;
    }

    public long getExpirationTime() {
        return expirationTime;
    }

    public void setExpirationTime(int stampRenewsInput) {
        this.expirationTime += 5000 * (stampRenewsInput/3);
    }

    public void setStampRenews(int stampRenewsInput) {
        this.stampRenews = stampRenewsInput;
    }

    public int getStampRenews() {
        return stampRenews;
    }

    public String getAuthor() { return ""; }
    public void setAuthor(String authorInput) {}

    public String getPublishingCompany() {return "";}
    public void setPublishingCompany(String publishingCompanyInput) {}
}

public class Novel extends Book {
    public String author;

    public Novel(String title, int page, String authorInput) {
        super(title, page);
        author = authorInput;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String authorInput) {
        this.author = authorInput;
    }
}

public class Textbook extends Book {
    public String publishingCompany;

    public Textbook(String title, int page, String publishingCompanyInput) {
        super(title, page);
        publishingCompany = publishingCompanyInput;
    }

    public String getPublishingCompany() {
        return publishingCompany;
    }

    public void setPublishingCompany(String publishingCompanyInput) {
        this.publishingCompany = publishingCompanyInput;
    }
}

public class Main {
    public void toString(ArrayList<Book> bookList) {
        String output = "[";
        for (int i = 0; i < bookList.size(); i++) {
            if (i == bookList.size() - 1) {
                output += "{" + bookList.get(i).getTitle() + "-" + bookList.get(i).getPage() + "-" + bookList.get(i).getID() + "-" + bookList.get(i).getTime() + "-" + bookList.get(i).getExpirationTime() + "}";
            } else {
                output += "{" + bookList.get(i).getTitle() + "-" + bookList.get(i).getPage() + "-" + bookList.get(i).getID() + "-" + bookList.get(i).getTime() + "-" + bookList.get(i).getExpirationTime() + "},";
            }
        }
        output += "]";
        System.out.println(output);
    }

    public int getBookCount(ArrayList<Book> bookList) {
        return bookList.size();
    }

    public long getShelfLife(Book bookInQuestion) {
        long shelfLife = System.currentTimeMillis() - bookInQuestion.getTime();
        return shelfLife;
    }

    public void checkIfExpired(Book bookInQuestion, long shelfLife) {
        boolean expired = false;
        if (shelfLife > bookInQuestion.getExpirationTime()) {
            expired = true;
        }
        System.out.println("Expired: " + expired);
    }

    public static void main(String[] args) throws InterruptedException {
        System.out.println("Part 1:");
        System.out.println("-------");
        ArrayList<Book> bookList = new ArrayList<Book>();
        Book book1 = new Book("Maze Runner", 500);
        Book book2 = new Book("Hunger Games", 700);
        Book book3 = new Book("Fahrenheit 451", 800);
        bookList.add(book1);
        bookList.add(book2);
        bookList.add(book3);
        Main myObj = new Main();
        System.out.println("All books in library:");
        System.out.println(book1.getTitle());
        System.out.println(book2.getTitle());
        System.out.println(book3.getTitle());
        System.out.println("");
        System.out.println("Number of books in library:");
        System.out.println(myObj.getBookCount(bookList));
        System.out.println("");
        System.out.println("toString():");
        myObj.toString(bookList);

        System.out.println();
        System.out.println("Part 2:");
        System.out.println("-------");
        bookList.clear();
        Book novel1 = new Novel("Computer Science Fundamentals", 800, "Mark Wahlberg");
        Book textbook1 = new Textbook("How to be good", 700, "Generic Publishing Company");
        bookList.add(novel1);
        bookList.add(textbook1);
        System.out.println("Author of novel: " + novel1.getAuthor());
        textbook1.setPublishingCompany("Specific Publishing Company");
        System.out.println("Publishing company of textbook: " + textbook1.getPublishingCompany());
        System.out.println("Date and time novel was added to library: " + novel1.getTime());
        myObj.toString(bookList);

        System.out.println();
        System.out.println("Part 3:");
        System.out.println("-------");
        Book newBook = new Book("Baron's Computer Science Adventures", 500);
        bookList.add(newBook);
        myObj.toString(bookList);
        Thread.sleep(3500);
        System.out.println(myObj.getShelfLife(newBook));
        myObj.checkIfExpired(newBook, myObj.getShelfLife(newBook));
        Thread.sleep(1500);
        System.out.println(myObj.getShelfLife(newBook));
        myObj.checkIfExpired(newBook, myObj.getShelfLife(newBook));

        Book newBookAgain = new Book("Generic Book", 700);
        bookList.add(newBookAgain);
        newBookAgain.setExpirationTime(3);
        Thread.sleep(6000);
        System.out.println(myObj.getShelfLife(newBookAgain));
        myObj.checkIfExpired(newBookAgain, myObj.getShelfLife(newBookAgain));
    }
}

Main.main(null);

Part 1:
-------
All books in library:
Maze Runner
Hunger Games
Fahrenheit 451

Number of books in library:
3

toString():
[{Maze Runner-500-0-1682699976779-5000},{Hunger Games-700-1-1682699976779-5000},{Fahrenheit 451-800-2-1682699976779-5000}]

Part 2:
-------
Author of novel: Mark Wahlberg
Publishing company of textbook: Specific Publishing Company
Date and time novel was added to library: 1682699976851
[{Computer Science Fundamentals-800-3-1682699976851-5000},{How to be good-700-4-1682699976851-5000}]

Part 3:
-------
[{Computer Science Fundamentals-800-3-1682699976851-5000},{How to be good-700-4-1682699976851-5000},{Baron's Computer Science Adventures-500-5-1682699976868-5000}]
3504
Expired: false
5009
Expired: true
6001
Expired: false