Creating Book Class in Java

Problem:

Write a class named Book that keeps track of book objects such that the instance data contains the book’s title and author and a unique identification number, say id that starts form 1 for the first book object and is incremented by 1 each time a new book with at least the title specified is created. The required methods in the Book class are as follows:

• 3 constructors: One without parameters that sets the title and author to “unknown” and id to 0; one with a single parameter that sets the title to the given value as parameter, sets the author to “unknown”, increments the sequence by 1 and sets id to this sequence number; one with two parameters for title and author, setting the corresponding instance data, and id as in the second constructor.
• The setter methods for title and author.
• The getter methods for title, author, and id.
• The equals method that compares the current book object with another Book object given as a parameter and returns true if both objects have the same title and author properties, and false otherwise.
• The toString method that returns a text including the book’s title, author and id. Refer to the sample execution window for the test program for details.
• The getInitials method that returns the initial letters of the author’s first name(s) and last name, if the author’s name is known (not equal to “unknown”, or not null).Assume that there can be at most two names and one surname separated by a single blank. Refer to the sample execution window for the test program for details.

Write a driver class that tests the Book class. Allow the user to enter as many book objects as s/he wants. Take care of necessary object initializations. Store the first and last book objects separately. Print each book object. Compare the first and last book objects, if any, and display a proper message if they are the same. Display the last book’s author’s initials, if the user has input any valid book object.

Sample execution windows:

To end the input process bypass each question by typing the enter key!

Type the title of the book:

Type the name of the author:

Press any key to continue...

To end the input process bypass each question by typing the enter key!

Type the title of the book: Windows NT Server 4.0

Type the name of the author: Russel

Book No: 1 entitled "Windows NT Server 4.0" written by Russel

Type the title of the book:

Type the name of the author:

First and last books are same

Last book's author has the initials, R.

Press any key to continue...

To end the input process bypass each question by typing the enter key!

Type the title of the book: Java Software Solutions

Type the name of the author: Lewis Loftus

Book No: 1 entitled "Java Software Solutions" written by Lewis Loftus

Type the title of the book: Introduction to Java Programming with JBuilder

Type the name of the author: Yvet Daniel Liang

Book No: 2 entitled "Introduction to Java Programming with JBuilder" written by

Yvet Daniel Liang

Type the title of the book:

Type the name of the author:

Last book's author has the initials, Y.D.L.

Press any key to continue...

Solution:

public class Book
{
 private String author, title;
 private int id;
 private static int identification =0;
 
 public Book()
 {
  title = author = "unknown";
  id = 0;
 }
 public Book(String title)
 {
  this.title = title;
  author = "unknown";
  identification++;
  id = identification;
 }
 public Book (String title, String author)
 {
  this.title = title;
  this.author = author;
  identification++;
  id = identification;
 }
 
 public void setTitle(String title)
 {
  this.title = title;
 }
 
 public void setAuthor(String author)
 {
  this.author = author;
 }
 
 public String getTitle()
 {
  return title;
 }
 public String getAuthor()
 {
  return author;
 }
 public int getId()
 {
  return id;
 }
 
 public boolean equals(Book other)
 {
  boolean enough = true;
  String otherAuthor = other.getAuthor();
  String otherTitle = other.getTitle();
  if(otherAuthor.equals(author) && otherTitle.equals(title))
   enough = true;
  else 
   enough = false;
  return enough;
 }
 public String getInitials ()
 {
  String output = "";
  if (!(author.equals("")) && !
          (author.equals("unknown")) && !(author.equals(null))) {
   output += author.charAt(0);
   output += ". ";
   if (author.indexOf(" ") != -1) {
   output += author.charAt(author.indexOf(" ") + 1);
   output += ". "; }
   
   if (author.indexOf(" ") != -1) {
   output += author.charAt((author.indexOf(" ") 
                         + author.indexOf(" ")) +4 );
   output += ". "; }
  }
  return output;
 }
 public String toString()
 {
  return "Book No: " + id + " entitled \"" 
                + title + "\"" + " written by " + author;
 }
}

import java.util.Scanner;
public class BookTest
{
 public static void main (String[] args)
 {
  Book firstBook = new Book();
        Book lastBook = new Book();
        Book aBook = new Book();
        
  Scanner scan = new Scanner (System.in);
  System.out.println("To end the input " +
       "process bypass each question by typing the enter key!");
  System.out.print("Type the title of the book: ");
  String title = scan.nextLine();
  System.out.print("Type the name of the author: ");
  String author = scan.nextLine();
  
  aBook = new Book(title, author);

  if (!(title.equals("") && author.equals("")))
  System.out.println(aBook);
  
  while (!(title.equals("") && author.equals("")))
  {
    if (aBook.getId() == 1)
     firstBook = aBook;
    System.out.print("Type the title of the book: ");
    title = scan.nextLine();
    System.out.print("Type the name of the author: ");
    author = scan.nextLine();
    if (!(title.equals("") && author.equals(""))) {  
     aBook = new Book(title, author);
    System.out.print(aBook);
    System.out.println(); }
  }
  lastBook = aBook;
  if (firstBook.equals(lastBook))
   System.out.println("First and last books are the same");
  System.out.println(lastBook.getInitials());
    
  
 }
}