Question

JAVA

Objective :

• Learning how to write a simple class.

• Learning how to use a prewritten class.

• Understanding how object oriented design can aid program design by making it easier to incorporate independently designed pieces of code together into a single application.

Instructions: • Create a project called Lab13 that contains three Java file called Book.java , Bookstore.java and TempleBookstore.java

• I’ve provided a screenshot of how your project should look like. • Be sure to document your code (add comments on top of your java file).

• In the comments add your name, date, course, homework number, and statement of problem. • Make sure your output matches mine (I attached a demo file for your convenience).

• Once you are done, Zip Lab13 project and upload through Blackboard.

Description: In this assignment, you will essentially write a console application that runs a simple bookstore. Three classes will be used in this homework: Book , Bookstore and TempleBookstore .

1. I’ve provided half - way written class called Bookstore that you need to co mplete ( it is posted in Blackboard next to the assignment description). You can add it to your project. You will just use the methods in Bookstore class only . The methods of Bookstore class are given below.

2. You have to implement a class called Book as described below. The name of this class MUST be Book and it MUST contain the instance methods below. Do not change the names of the methods, because they are accessed from the Bookstore class.

3. You also have to implement another class called TempleBooks tore . This class will contain only a main method. In this main method, you will create a Bookstore object first, and then you will perform certain menu - driven operations using this Bookstore object and the methods in the Bookstore class.

Book

The Book class needs to written by you. A Book object keeps track of information for one particular book that could potentially be stored in a bookstore. Here are the instance variables/fields for this class:

private String title;

private int numOfPages;

private double price;

private int quantity;

// Constructor: Takes in the title of the book, the number of pages in the book, the cost of the book and

// the number of copies (quantity) of books and initializes each of the appropriate instances variables in

//the object.

public Book(String thetitle, int pages, double cost, int num)

// Returns the title of the Book object the method is called on.

public

String getTitle()

// Returns the price of the Book object the method is called on.

public double getPrice()

// Returns the quantity of the Book object the method is called on.

public int getQuantity()

// Returns all the information about a Book object

as a String. (Add spaces or tabs to make it readable!)

public String toString()

// Decrements the number of copies, by the given amount, for the Book object the method is called on.

public void subtractQuantity(int amount)

//Increments the number of copi

es, with the given amount, for the Book object the method is called on.

public void addQuantity(int amount)

Bookstore

You need to use the methods in Bookstore class in order to create your console application that will "run" a bookstore. Here are the instance methods in that class:

// Constructor that creates a new, empty Bookstore object.

public Bookstore()

// Adds a new Book b to the stock of the Bookstore object.

public void addNewBook(Book b)

// Adds quantity number of books to the book already

in stock in the Bookstore object with

// the title title. If the book is not in the Bookstore object, nothing is done.

public void addBookQuantity(String title, int quantity)

// Returns true if quantity or more copies of a book with the title title are co

ntained in the Bookstore object.

public boolean inStock(String title, int quantity)

//

Executes

selling quantity number of books from the Bookstore object with the title title to the

// buyer. (Note: there is no I/O done in this method, the Bookstore obje

ct is changed to reflect

// the sale. The method returns true is the sale was executed successfully, false otherwise.

public boolean sellBook(String title, int quantity);

// Lists all of the titles of the books in the Bookstore object.

public void

listTitles()

// Lists all of the information about the books in the Bookstore object.

public void listBooks()

// Returns the total gross income of the Bookstore object.

public double getIncome()

The TempleBookstore class should contain only a main method. In this main method, you will create a Bookstore object first, and then you will perform certain menu

-

driven operations using this

Bookstore

object and the methods in this class. The main method of your

TempleBookstore

class should do the

following:

•

Create a new Bookstore

object.

•Prompt the user with the following menu choice

1) Add a book to the stock

2) Sell a book in stock

3) List the titles of all the books in stock (in the Bookstore object)

4)

List all the information about the books in stock (in the Bookstore object)

5) Print out the gross income of the bookstore

6) Quit

Execute the choice the user chooses and then continue until they quit.

•What each menu choice should do:

1.Adding a book

:

Ask the user for the title of the book. If it is already in stock, simply ask the user to enter how many extra books to stock, and then do so. If not, ask the user for the rest of the information (number of pages, price, and quantity) and add that book into the stock.

2.Selling a book: Ask the user for the title of the book they want to buy. If it is not in stock, print a message to that effect. Otherwise,ask the user how many copies of that book they want to buy. If there are enough copies of the book, make the sale. If not, print out a message explaining why the transaction could not be completed.

3.List the titles of all the books in stock(in the Bookstore object)

4.List all the information about the books in stock(in the Bookstore object)

5.Print out the gross income of the bookstore

6.Quit

Answer 1

$\color{blue}\underline{Book.java:}$

public class Book {

    private String title;
    private int numOfPages;
    private double price;
    private int quantity;

    public Book(String title, int numOfPages, double price, int quantity) {
        this.title = title;
        this.numOfPages = numOfPages;
        this.price = price;
        this.quantity = quantity;
    }

    public String getTitle() {
        return title;
    }

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

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public int getQuantity() {
        return quantity;
    }

    public void setQuantity(int quantity) {
        this.quantity = quantity;
    }

    public void subtractQuantity(int amount){
        if(amount > 0 && quantity >= amount)
            quantity -= amount;
    }

    public void addQuantity(int amount){
        if(amount > 0)
            quantity += amount;
    }

    @Override
    public String toString() {
        return "Book{" +
                "title='" + title + '\'' +
                ", numOfPages=" + numOfPages +
                ", price=" + price +
                ", quantity=" + quantity +
                '}';
    }
}

$\color{blue}\underline{BookStore.java:}$

import java.util.ArrayList;
import java.util.List;

public class BookStore {

    private List<Book> books;
    private double income;

    public BookStore() {
        books = new ArrayList<>();
    }

    public void addNewBook(Book b){
        books.add(b);
    }

    private Book findBook(String title){
        for(int i = 0; i < books.size(); ++i){
            if(books.get(i).getTitle().equalsIgnoreCase(title))
                return books.get(i);
        }
        return null;
    }

    public void addBookQuantity(String title, int quantity){
        Book book = findBook(title);
        if(book != null){
            book.addQuantity(quantity);
        }
    }

    public boolean inStock(String title, int quantity){
        Book book = findBook(title);
        if(book != null){
            return book.getQuantity() > 0;
        }
        return false;
    }

    public boolean sellBook(String title, int quantity){
        Book book = findBook(title);
        if(book != null){
            if(book.getQuantity() >= quantity){
                book.subtractQuantity(quantity);
                income += book.getPrice() * quantity;
                return true;
            }
        }
        return false;
    }

    public void listTitles(){
        for(int i = 0; i < books.size(); ++i){
            System.out.println(books.get(i).getTitle());
        }
    }

    public void listBooks(){
        for(int i = 0; i < books.size(); ++i){
            System.out.println(books.get(i).toString());
        }
    }

    public double getIncome(){
        return income;
    }

}