Book

public class Book {
    private int totalPages, totalChapters;
    private double unitPrice;
    private String title, author, ISBN;
    protected String format = "Paper"; // need to take this value
    private static final double DEFAULT_UNIT_PRICE = 15.00;

    public Book(String title, String author,
            String ISBN, int totalPages, int totalChapters, double unitPrice) {
        this.totalPages = totalPages;
        this.totalChapters = totalChapters;
        this.unitPrice = (unitPrice <= 0) ? DEFAULT_UNIT_PRICE : unitPrice;
        this.title = title;
        this.author = author;
        this.ISBN = ISBN;
    }

    public int getTotalPages() {
        return totalPages;
    }

    public void setTotalPages(int totalPages) {
        this.totalPages = totalPages;
    }

    public int getTotalChapters() {
        return totalChapters;
    }

    public void setTotalChapters(int totalChapters) {
        this.totalChapters = totalChapters;
    }

    public double getUnitPrice() {
        return unitPrice;
    }

    public void setUnitPrice(double unitPrice) {
        this.unitPrice = unitPrice;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getAuthor() {
        return author;
    }

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

    public String getISBN() {
        return ISBN;
    }

    public void setISBN(String ISBN) {
        this.ISBN = ISBN;
    }

    public String getFormat() {
        return format;
    }

    @Override
    public String toString() {
        return "\nTitle: " + this.title +
                "\nAuthor: " + getAuthor() +
                "\nISBN: " + this.getISBN() +
                "\nNo. of Pages: " + totalPages +
                "\nNo. of Chapters: " + this.getTotalChapters() +
                "\nUnit Price: $" + unitPrice;
    }
}