Question

JAVA Programming ECLIPSE IDE

1.

Create an abstract class called Book. The class should declare the following variables:
an instance variable that describes the title - String
an instance variable that describes the ISBN - String
an instance variable that describes the publisher - String
an instance variable that describes the price - double
an instance variable that describes the year – integer

Provide a toString() method that returns the information stored in the above variables.

Create the getter and setter methods for each instance variable except price. Provide the necessary constructors. Include an abstract method setPrice(double price) to determine the price for a book. Include an abstract method getGenre() to return the genre of the book.

Create two subclasses called ScienceBook and ChildrenBook.

These subclasses should override the abstract methods setPrice and getGenre of class Book.

Use the following rule for setting the price for a book:
science books will have a 10% discount per each book
children books will have a fixed price (specified by user).

Write a driver program (another class with main method) that uses the above hierarchy. In your driver program you must implement an interaction with the user.
Use showInputDialog method to let the user input book information.
Use showMessageDialog method to display book information including price and type for both science and children books.

Answer 1

Implementation in JAVA;

Code;

import java.util.Scanner;

// Tester Class
public class Tester {

//   driver function
   public static void main(String[] args) {
      
//       showInputDialog method
      
       ScienceBook sb= InputDialog_ScienceBook();
      
       ChildrenBook cb= InputDialog_ChildrenBook();
         
      
      
//       Print details
      
       print_ScienceBook(sb);
  
       print_ChildrenBook(cb);
      

   }
  
//   showMessageDialog of Children book
   public static void print_ChildrenBook(ChildrenBook cb) {
      
System.out.println("\nOutput Details of Children Book: ");
      
       System.out.println(cb.toString());
      
   }
  
//   showMessageDialog of science book
   public static void print_ScienceBook(ScienceBook sb) {
      
   System.out.println("\nOutput Details of Children Book: ");
          
           System.out.println(sb.toString());
          
       }
  
//   showInputDialog method of Science book
   public static ScienceBook InputDialog_ScienceBook() {
      
//       take inputs of Science Book
       Scanner s= new Scanner(System.in);
      
       System.out.println("Enter Details for Science Book \n");
      
       System.out.print("Enter Title of Book : ");
       String title = s.next();
       System.out.print("Enter ISBN of Book : ");
       String isbn = s.next();
       System.out.print("Enter Publisher of Book : ");
       String publisher = s.next();
       System.out.print("Enter price of Book $: ");
       double price = s.nextDouble();
       System.out.print("Enter Year of publishment of Book : ");
       int year = s.nextInt();

       System.out.print("Enter Genre of Book : ");
       String genre = s.next();
      
//       create object and call constructor
       ScienceBook sb= new ScienceBook(title, isbn, publisher, price, year, genre);
      
       return sb;
      
   }
  
  
//   showInputDialog method of Children book
   public static ChildrenBook InputDialog_ChildrenBook() {
      
       Scanner s= new Scanner(System.in);
      
//       take inputs of Children Book
System.out.println("\n\nEnter Details for Children Book \n");
      
       System.out.print("Enter Title of Book : ");
       String title1 = s.next();
       System.out.print("Enter ISBN of Book : ");
       String isbn1 = s.next();
       System.out.print("Enter Publisher of Book : ");
       String publisher1 = s.next();
       System.out.print("Enter price of Book $: ");
       double price1 = s.nextDouble();
       System.out.print("Enter Year of publishment of Book : ");
       int year1 = s.nextInt();

       System.out.print("Enter Genre of Book : ");
       String genre1 = s.next();
      
//       create object and call constructor
      
       ChildrenBook cb= new ChildrenBook(title1, isbn1, publisher1, price1, year1, genre1);
      
       return cb;
      
   }

  
  
}

// Abstract Class book
abstract class Book{
  
  
//   Instance variables
   String title;
  
   String ISBN;
  
   String publisher;
  
   double price;
  
   int year;
  
//   constructor
   public Book(String title, String ISBN, String publisher, double price,int year) {
      
       this.title = title;
       this.ISBN = ISBN;
       this.publisher = publisher;
       this.price=price;
       this.year=year;
      
   }
  
  
//   getters and setters
   public String gettitle() {
       return title;
   }
  
   public void settitle(String title) {
       this.title= title;
   }
  
   public String getISBN() {
       return ISBN;
   }
  
   public void setISBN(String ISBN) {
       this.ISBN= ISBN;
   }
  
   public String getpublisher() {
       return publisher;
   }
  
   public void setpublisher(String publisher) {
       this.publisher= publisher;
   }
  
   public int getyear() {
       return year;
   }
  
   public void setyear(int year) {
       this.year= year;
   }
  
   public double getprice() {
  
       return price;
   }
  
//   to string method
   public String toString() {
      
       String ans="Title : "+title+"\nISBN : "+ISBN+"\nPublisher : "+publisher+"\nYear : "+year;
      
       return ans;
   }
  
  
//   abstract methods
   abstract String getgenre() ;
  
   abstract void setPrice(double price);
  
}

// class ScienceBook extends Book class which implements unimplemented methods
class ScienceBook extends Book{

//   instance variables
   String genre;
     
   int discount = 10;
     
//   call constructor
   public ScienceBook(String title, String ISBN, String publisher, double price, int year, String genre) {
       super(title, ISBN, publisher, price, year);
       this.genre=genre;
      
   }
  
  
   @Override
   String getgenre() {
      
       return genre;
   }

   @Override
   void setPrice(double price) {
      
   this .price = price - (discount*price/100);
      
      
   }
  
  
   @Override
   public String toString() {
  
   setPrice(price);
      
       String ans = super.toString()+"\nPrice $: "+price+" (After 10% discount)" + "\nGenre : "+genre;
      
      
      
       return ans;
      
   }
     
     
     
}


class ChildrenBook extends Book{
     
   String genre;

//   super constructor
   public ChildrenBook(String title, String ISBN, String publisher, double price, int year, String genre) {
       super(title, ISBN, publisher, price, year);
       this.genre=genre;
      
   }

   @Override
   String getgenre() {
  
       return genre;
   }

   @Override
   void setPrice(double price) {
      
       this.price = price;
   }
  
   @Override
   public String toString() {
      
       String ans = super.toString() +"\nPrice $: "+price+" (Fixed price )"+ "\nGenre : "+genre;
      
       return ans;
      
   }
     
     
     
}

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