Sample: LibraryCard

LibraryCard.java,  Librarian.java

/*

    Introduction to OOP with Java (5th Ed), McGraw-Hill

    Wu/Otani

    File: LibraryCard.java

*/

class LibraryCard {

    // Data Members  

   

    //student owner of this card

    private Student owner;

   

    //number of books borrowed

    private int borrowCnt;

   

    //numOfBooks are checked out

    public void checkOut(int numOfBooks) {

        borrowCnt = borrowCnt + numOfBooks;

    }

   

    //Returns the name of the owner of this card

    public String getOwnerName( ) {

        return owner.getName( );

    }

   

    //Returns the number of books borrowed

    public int getNumberOfBooks( ) {

        return borrowCnt;

    }

   

    //Sets the owner of this card to student

    public void setOwner(Student student) {

        owner = student;

    }

   

   

    //Returns the string representation of this card

    public String toString( ) {

        return  "Owner Name:     " + owner.getName( ) + "\n" +

                "      Email:    " + owner.getEmail( ) + "\n" +

                "Books Borrowed: " + borrowCnt;

    }

      

 }

//-----------------

/*

    Introduction to OOP with Java (5th Ed), McGraw-Hill

    Wu/Otani

    File: Librarian.java

*/

class Librarian {

  

    public static void main( String[] args ) {

   

        Student    student;

        LibraryCard card1, card2;

       

        student = new Student( );

        student.setName("Jon Java");

        student.setEmail("jj@javauniv.edu");

       

        card1 = new LibraryCard( );

        card1.setOwner(student);

        card1.checkOut(3);

       

        card2 = new LibraryCard( );

        card2.setOwner(student); //the same student is the owner

                                 //of the second card, too

       

        System.out.println("Card1 Info:");

        System.out.println(card1.toString() + "\n");

       

        System.out.println("Card2 Info:");

        System.out.println(card2.toString() + "\n");

      

    }

}