Private instance variables/Class Definitions

Question

I am trying to solve this problem:

A Book, which as a title, author, and year of publication. Include methods to get and set the private instance variables and a toString method to display the object. Also create a method moreRecent which takes two books as input parameters and returns the one that was published more recently. Create 3 JUnit tests for moreRecent.

However, I don't know how to access the other private instance variables author and yearofPub. I can only do one constructor per class right? So how do I get the other 2 variables? This is my code so far: Thanks!

class Book {
private String title;
private String author;
private String yearofPub;

Book(String input) {
    title = input;
}


String moreRecent(int Book1, int Book2) {
    String moreRecent;
    if(Book1 > Book2) {
        moreRecent = "Book 1";
    }
    if (Book2 > Book1) {
        moreRecent = "Book 2";
    }
    else 
        moreRecent = "Both";
    return moreRecent;

}

}

public class Chpt2930BookTitleAuthorYear {

/**
 * @param args the command line arguments
 */
public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    System.out.println("Enter title of Book: ");
    String nextLine = scan.next();
    Book titleofBook = new Book(nextLine);

}
}

EDIT--------------------------

Ok thanks for all the responses! I improved my code further but am still not able to get a correct result. I'm especially having difficulty with the method moreRecent. How do I set the yearofPub for those books? Here is my code:

class Book {

private String title;
private String author;
private String yearofPub;

Book(String input) {
    title = input.toString();
}

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 getYearofPub() {
    return yearofPub;
}

public void setYearofPub(String yearofPub) {
    this.yearofPub = yearofPub;
}

public String toString() {
    System.out.println("Book{" + "Title=" + title + " Author=" + author + " Year of
      Publication=" + yearofPub + "}");
    return " ";
}
//confused on this part :(
String moreRecent(Book Book1, Book Book2) {
    if (Book1.getYearofPub>Book.getYearofPub) { //Is this correct? I'm not sure :/

    }
}
}

public class Chpt2930BookTitleAuthorYear {

/**
 * @param args the command line arguments
 */
public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    System.out.println("Enter title of Book: ");
    String nextLineTitle = scan.nextLine();
    Book titleofBook = new Book(nextLineTitle);


    System.out.println("Enter author of the Book: ");
    String nextLineAuthor = scan.nextLine();
    titleofBook.setAuthor(nextLineAuthor);


    System.out.println("Enter the date of publication of the Book: ");
    String nextLineDate = scan.nextLine();
    titleofBook.setYearofPub(nextLineDate);

    titleofBook.toString();

}
}

Thanks!

EDIT 2-----------------

Nvm'd I found the problem :) Thanks for all the help though

Answer 1

Do this:

class Book {

    private String title;
    private String author;
    private String yearofPub;

    Book(String input) {
        title = input;
    }

    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 getYearofPub() {
        return yearofPub;
    }

    public void setYearofPub(String yearofPub) {
        this.yearofPub = yearofPub;
    }



}

And in your main method, you can:

Book titleofBook = new Book(nextLine);
titleofBook.setAuthor(...) 

Answer 2

Provide the so called accessors for the variables. For example:

public String getAuthor() { 
   return this.author; 
}

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

Same goes for the yeaofPub field.