/* * @(#)Book.java 1.1 97/12/12 * * Copyright (c) 1997 Sun Microsystems, Inc. All Rights Reserved. * * This software is the confidential and proprietary information of Sun * Microsystems, Inc. ("Confidential Information"). You shall not * disclose such Confidential Information and shall use it only in * accordance with the terms of the license agreement you entered into * with Sun. * * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF THE * SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR * PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR ANY DAMAGES * SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING * THIS SOFTWARE OR ITS DERIVATIVES. * */ import java.io.*; class Book extends ReadingMaterial implements Serializable { int numpages; String name; boolean ishardcover; // other relevant information and methods // . // . // . Book(int pages, String n, boolean hardcover, String author, String subject, int yearwritten) { super(author, subject, yearwritten); numpages = pages; name = n; ishardcover = hardcover; } /** * Saves its own fields by calling defaultWriteObject and then explicitly * saves the fields of its supertype */ private void writeObject(ObjectOutputStream out) throws IOException { // Take care of this class's field first by calling defaultWriteObject out.defaultWriteObject(); /* * Since the superclass does not implement the Serializable interface * we explicitly do the saving... Since these fields are not private * we can access them directly. If they were private, the superclass * would have to implement get and set methods that would allow the * subclass this necessary access for proper saving. */ out.writeObject(author); out.writeObject(subject); out.writeInt(yearwritten); } /** * Restores its own fields by calling defaultReadObject and then explicitly * restores the fields of its supertype. */ private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException { /* * Take care of this class's fields first by calling * defaultReadObject */ in.defaultReadObject(); /* * Since the superclass does not implement the Serializable * interface we explicitly do the restoring... Since these fields * are not private we can access them directly. If they were * private, the superclass would have to implement get and set * methods that would allow the subclass this necessary access * for proper saving or restoring. */ author = (String) in.readObject(); subject = (String) in.readObject(); yearwritten = in.readInt(); } /** Print out the field values. Useful for testing. */ public String toString() { return("Name: " + name + "\n" + "Author: " + author + "\n" + "Pages: " + numpages + "\n" + "Subject: " + subject + "\n" + "Year: " + yearwritten + "\n"); } }