THE Java™ Programming Language, Fourth Edition

1 THE Java Programming language , Fourth EditionBy Ken Arnold, James Gosling, David : Addison Wesley ProfessionalPub Date: August 17, 2005 ISBN: 0-321-34980-6 Pages: 928 Table of Contents | IndexDirect from the creators of the Java Programming language , the completely revised Fourth Edition of TheJava Programming language is an indispensable resource for novice and advanced programmers around the world have used previous editions to quickly gain a deep understanding of the Javaprogramming language , its design goals, and how to use it most effectively in real-world development. Now,Ken Arnold, James Gosling, and David Holmes have updated this classic to reflect the major enhancementsin Java 2 Standard Edition (J2SE ).The authors systematically cover most classes in Java's main packages, *, , and ,presenting in-depth explanations of why these classes work as they do, with informative examples. Severalnew chapters and major sections have been added, and every chapter has been updated to reflect today's bestpractices for building robust, efficient, and maintainable Java changes in this Edition includeNew chapters on generics, enums, and annotations, the most powerful new language featuresintroduced in J2SE Changes to classes and methods throughout to reflect the addition of generics Major new sections on assertions and regular expressions Coverage of all the new language features, from autoboxing and variable argument methods to theenhanced for-loop and covariant return types Coverage of key new classes, such as Formatter and Scanner The Java Programming language , Fourth Edition , is the definitive tutorial introduction to the Javalanguage and essential libraries and an indispensable reference for all programmers, including those withextensive experience.

2 It brings together insights you can only get from the creators of Java: insights that willhelp you write software of exceptional Java Programming language , Fourth EditionBy Ken Arnold, James Gosling, David : Addison Wesley ProfessionalPub Date: August 17, 2005 ISBN: 0-321-34980-6 Pages: 928 Table of Contents | IndexCopyright11 TheJava SeriesPrefaceAboutThisBookExamplesandDoc umentationAcknowledgments(FourthEdition) Acknowledgments(ThirdEdition)Acknowledgm ents(SecondEdition)Acknowledgments(First Edition )Chapter 1. OtherTopicsBrieflyNotedChapter 2. NativeMethodsChapter 3. SingleInheritanceversusMultipleInheritan ceChapter 4. WhentoUseInterfacesChapter 5. ImplementationofNestedTypesChapter 6. ToEnumorNotChapter 7. Tokens,Values, TheMeaningsofNamesChapter 8. BoxingConversionsChapter 9. MemberAccessChapter 10. What,Nogoto?

3 Chapter 11. ClassExtensionandGenericTypesChapter 12. try,catch, TurningAssertionsOnandOffChapter 13. WorkingwithUTF-16 Chapter 14. wait,notifyAll, ThreadManagement,Security, DebuggingThreadsChapter 15. WorkingwithAnnotationsChapter 16. ControllingAssertionsatRuntimeChapter 17. ReachabilityStatesandReferenceObjectsCha pter 18. PackageObjectsandSpecificationsChapter 19. NotesonUsageChapter 20. ATasteofNewI/O1818 Chapter 21. PropertiesChapter 22. MathandStrictMathChapter 23. SecurityChapter 24. Time,Dates, InternationalizationandLocalizationforTe xtChapter 25. javax.* A. Language, Library, Generics:Reification,Erasure,andRawTypes Appendix B. UsefulTablesFurtherReadingJavaPlatformTo picsObject-OrientedDesignMultithreadedPr ogrammingGenericsRegularExpressionsGener alProgrammingTechniquesRelatedLanguagesS oftwareEngineeringVisualDesign&GUID esignColophonNotetoTranslatorsArticle242 4 ExercisesQuotesIndexCopyright 2006 Sun Microsystems, Network Circle, Santa Clara, California 95054 rights , duplication, or disclosure by the United States Government is subject to the restrictions set forth inDFARS (c)(1)(ii) and FAR release described in this book may be protected by one or more patents, foreign patents, or Microsystems, Inc.

4 (SUN) hereby grants to you a fully-paid, nonexclusive, nontransferable, perpetual,worldwide limited license (without the right to sublicense) under SUN's intellectual property rights that areessential to practice this specification. This license allows and is limited to the creation and distribution ofclean room implementations of this specification that: (i) include a complete implementation of the currentversion of this specification without subsetting or supersetting; (ii) implement all the interfaces andfunctionality of the standard java.* packages as defined by SUN, without subsetting or supersetting; (iii) donot add any additional packages, classes or methods to the java.* packages; (iv) pass all test suites relating tothe most recent published version of this specification that are available from SUN six (6) months prior to anybeta release of the clean room implementation or upgrade thereto; (v) do not derive from SUN source code orbinary materials; and (vi) do not include any SUN binary materials without an appropriate and separatelicense from , Sun Microsystems, Sun Microsystems Computer Corporation, the Sun logo, the Sun MicrosystemsComputer Corporation logo, Java, JavaSoft, JavaScript JDBC, JDBC Compliant, JavaOS, JavaBeans andHotJava are trademarks or registered trademarks of Sun Microsystems, Inc.

5 UNIX is a registered trademarkin the United States and other countries, exclusively licensed through X/Open Company, Ltd. Apple andDylan are trademarks of Apple Computer, Inc. All other product names mentioned herein are the trademarksof their respective PUBLICATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHEREXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OFMERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR PUBLICATION COULD INCLUDE TECHNICAL INACCURACIES OR TYPOGRAPHICALERRORS. CHANGES ARE PERIODICALLY ADDED TO THE INFORMATION HEREIN; THESECHANGES WILL BE INCORPORATED IN NEW EDITIONS OF THE PUBLICATION. SUNMICROSYSTEMS, INC. MAY MAKE IMPROVEMENTS AND/OR CHANGES IN THE PRODUCT(S)AND/OR THE PROGRAM(S) DESCRIBED IN THIS PUBLICATION AT ANY of the designations used by manufacturers and sellers to distinguish their products are claimed astrademarks. Where those designations appear in this book, and the publisher was aware of a trademark claim,the designations have been printed with initial capital letters or in all authors and publisher have taken care in the preparation of this book, but make no expressed or impliedwarranty of any kind and assume no responsibility for errors or omissions.

6 No liability is assumed forincidental or consequential damages in connection with or arising out of the use of the information orprograms contained publisher offers excellent discounts on this book when ordered in quantity for bulk purchases or specialsales, which may include electronic versions and/or custom covers and content particular to your business,training goals, marketing focus, and branding interests. For more information, please contact: U. S. Corporateand Government Sales, (800) 382-3419, sales outside the U. S., please contact: International Sales, us on the Web: of Congress Cataloging-in-Publication DataArnold, Ken, 1958- The Java Programming language / Ken Arnold, James Gosling, David Holmes. p. cm. Includes bibliographical references and index. ISBN 0-321-34980-6 (pbk. : alk. paper) 1. Java (Computer program language ) I. Gosling, James. II. Holmes, David (David Colin) III. Title. 2005 '3--dc22 2005017029 All rights reserved.

7 Printed in the United States of America. This publication is protected by copyright, andpermission must be obtained from the publisher prior to any prohibited reproduction, storage in a retrievalsystem, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, orlikewise. For information regarding permissions, write to: Pearson Education, Inc., Rights and ContractsDepartment, One Lake Street, Upper Saddle River, NJ 07458 Text printed in the United States on recycled paper at Courier in Stoughton, printing, August 2005 DedicationThis book is dedicated to the Java team From whose hard work and vision A mighty oak has grownTo Judy and Lee, Taylor, and Java SeriesKen Arnold, James Gosling, David HolmesThe Java Programming language , Third Edition2626 Cynthia Bloch, Annette WagnerMIDP Style Guide for the Java 2 Platform, Micro EditionJoshua BlochEffective Java Programming language GuideMary Campione, Kathy Walrath, Alison HumlThe Java Tutorial, Third Edition : A Short Course on the BasicsMary Campione, Kathy Walrath, Alison Huml,Tutorial TeamThe Java Tutorial Continued: The Rest of the JDK Patrick ChanThe Java Developers Almanac , Volume 1 Patrick ChanThe Java Developers Almanac , Volume 2 Patrick Chan, Rosanna LeeThe Java Class Libraries, Second Edition , Volume 2.

8 , , Chan, Rosanna Lee, Doug KramerThe Java Class Libraries, Second Edition , Volume 1: , , , , , Chan, Rosanna Lee, Doug KramerThe Java Class Libraries, Second Edition , Volume 1: Supplement for the Java 2 Platform, StandardEdition, Chen, Li GongProgramming Open Service Gateways with Java Embedded ServerZhiqun ChenJava Card Technology for Smart Cards: Architecture and Programmer's GuideMaydene Fisher, Jon Ellis, Jonathan BruceJDBC API Tutorial and Reference, Third EditionLi Gong, Gary Ellison, Mary DagefordeInside Java 2 Platform Security, Second Edition : Architecture, API Design, and Implementation2727 James Gosling, Bill Joy, Guy Steele, Gilad BrachaThe Java language Specification, Third EditionDoug LeaConcurrent Programming in Java , Second Edition : Design Principles and PatternsRosanna Lee, Scott SeligmanJNDI API Tutorial and Reference: Building Directory-Enabled Java ApplicationsSheng LiangThe Java Native Interface: Programmer's Guide and SpecificationTim Lindholm, Frank YellinThe Java Virtual Machine Specification, Second EditionRoger Riggs, Antero Taivalsaari, Jim Van Peursem, Jyri Huopaniemi, Mark Patel, Aleksi UotilaProgramming Wireless Devices with the Java 2 Platform, Micro Edition , Second EditionSun Microsystems, Look and Feel Design Guidelines: Advanced TopicsKathy Walrath, Mary Campione, Alison Huml, Sharon ZakhourThe JFC Swing Tutorial, Second Edition : A Guide to Constructing GUIsSeth White, Maydene Fisher, Rick Cattell, Graham Hamilton, Mark HapnerJDBC API Tutorial and Reference, Second Edition : Universal Data Access for the Java 2 PlatformSteve Wilson, Jeff KesselmanJava Platform Performance.

9 Strategies and TacticsThe Jini Technology SeriesEric Freeman, Susanne Hupfer, Ken ArnoldJavaSpaces Principles, Patterns, and PracticeThe Java Series, Enterprise EditionStephanie Bodoff, Dale Green, Kim Haase, Eric JendrockThe J2EE Tutorial, Second EditionRick Cattell, Jim Inscore, Enterprise Partners2828J2EE Technology in Practice: Building Business Applications with the Java 2 Platform, EnterpriseEditionMark Hapner, Rich Burridge, Rahul Sharma, Joseph Fialli, Kim HaaseJava Message Service API Tutorial and Reference: Messaging for the J2EE PlatformInderjeet Singh, Beth Stearns, Mark Johnson, Enterprise TeamDesigning Enterprise Applications with the Java 2 Platform, Enterprise EditionVlada Matena, Sanjeev Krishnan, Linda DeMichiel, Beth StearnsApplying Enterprise JavaBeans , Second Edition : Component-Based Development for the J2EE PlatformBill Shannon, Mark Hapner, Vlada Matena, James Davidson, Eduardo Pelegri-Llopart, Larry Cable,Enterprise TeamJava 2 Platform, Enterprise Edition : Platform and Component SpecificationsRahul Sharma, Beth Stearns, Tony NgJ2EE Connector Architecture and Enterprise Application IntegrationPrefaceBeautiful buildings are more than scientific.

10 They are true organisms, spiritually conceived;works of art, using the best technology by inspiration rather than the idiosyncrasies of meretaste or any averaging by the committee Lloyd WrightThe Java Programming language has been warmly received by the world community of software developersand Internet content providers. Users of the Internet and World Wide Web benefit from access to secure,platform-independent applications that can come from anywhere on the Internet. Software developers whocreate applications in the Java Programming language benefit by developing code only once, with no need to"port" their applications to every software and hardware many, the language was known first as a tool to create applets for the World Wide Web. An applet is amini-application that runs inside a Web page. An applet can perform tasks and interact with users on theirbrowser pages without using resources from the Web server after being downloaded. Some applets may, ofcourse, talk with the server to do their job, but that's their Java Programming language is indeed valuable for distributed network environments like the , it goes well beyond this domain to provide a powerful general-purpose Programming languagesuitable for building a variety of applications that either do not depend on network features or want them fordifferent reasons.