package dbj.pjama;

import java.util.*;
import org.opj.*;

class Book {
  static { OPRuntime.roots.add (Book.class); }
  static HashMap extension = new HashMap ();
  String title, isbn;
  Vector authors;
  double price;

  public Book (String isbn) {
    this.isbn = isbn;
    price = 0.0;
    title = null;
    authors = new Vector ();
    extension.put (isbn, this);
  }

    public void setTitle (String s) {
    title = s;
    }

  public void addAuthor (Author a) {
    authors.add (a);
  }

  public String toString () {
    return "Book: " + isbn + ", " + title;
  }

  public static Book findBook (String isbn) {
    return (Book) extension.get (isbn);
  }

    public static Iterator books () {
	return extension.values ().iterator ();
    }
}