Java Enterprise Edition 1.4 Bible ™ James McGovern, Rahim Adatia, Yakov Fain, Jason Gordon, Ethan Henry, Walter Hurst, Ashish Jain, Mark Little, Vaidyanathan Nagarajan, Harshad Oak, Lee Anne Phillips Java Enterprise Edition 1.4 Bible ™ James McGovern, Rahim Adatia, Yakov Fain, Jason Gordon, Ethan Henry, Walter Hurst, Ashish Jain, Mark Little, Vaidyanathan Nagarajan, Harshad Oak, Lee Anne Phillips Java™ Enterprise Edition 1.4 Bible Published by Wiley Publishing, Inc 10475 Crosspoint Boulevard Indianapolis, IN 46256 www.wiley.com Copyright © 2003 by Wiley Publishing, Inc., Indianapolis, Indiana Published simultaneously in Canada ISBN: 0-7645-3966-3 Manufactured in the United States of America 10 1O/RS/QY/QT/IN No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, 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Publishing, Inc., is not associated with any product or vendor mentioned in this book is a trademark of Wiley Publishing, Inc About the Authors James McGovern is currently employed as an enterprise architect for Hartford Financial Services He is the coauthor of The Practical Guide to Enterprise Architecture (Prentice Hall, 2003), Java Web Services Architecture (Morgan Kaufmann, 2003), and Xquery — Kick Start (Sams Publishing, 2003) James has 16 years of experience in information technology He is a member of the Java Community Process, the IEEE, and the Worldwide Institute of Software Architects He holds industry certifications from Microsoft, Cisco, and Sun Rahim Adatia has been programming since he got his first computer — a TRS-80 — way back in the beginning of the ’80s Fortunately, he didn’t stagnate there and progressed on to developing large-scale enterprise architectures using C/C++, UML, CORBA, J2EE/EJB/Java, and now C# and NET He has applied his more than 15 years of experience to leading implementations at Charles Schwab, Williams Communications, Valtech, Nortel Networks, Corel Corporation, Lokah Limited, and T-Mobile International, to name a few Most recently, he has focused on the wireless middleware market, where he has led product development using Web services, J2EE, and NET He is also a delegate for T-Mobile International at the Open Mobile Alliance standards body Rahim has contributed to numerous books and articles throughout his career, including the books Professional EJB and J#, and is actively reviewing other titles He can be reached at rahimadatia@yahoo.com Yakov Fain has more than 20 years of experience in information technology and is an experienced architect, developer, instructor, and mentor He is the author of The Java Tutorial for the Real World Yakov is the principal of Smart Data Processing, Inc (http://www.smartdataprocessing.com), whose clients include major Wall Street companies He is a Sun Certified Java Programmer and a Sybase Certified Powerbuilder Developer Jason Gordon is a software engineer for Verizon and serves as lead for the Global Email system team While at Verizon he has played a variety of roles, including systems architect for the eBusiness Technology Integration and eInfrastructure group and key developer of the EDGE project, which helped provide a Web-based infrastructure to facilitate the merger of Bell Atlantic and GTE into Verizon Jason also served as a member of Verizon’s XML-Task Force and collaborated on several wireless and Web-services initiatives within the company In addition to being an active technical author, Jason also currently serves as the national technology coordinator for the National Society of Black Engineers He can be reached at jasontgordon@hotmail.com or http://www.jtgordon.com Ethan Henry has most recently worked as the manager of training services at Sitraka In previous positions he was a developer, product manager, and Java evangelist He has written numerous articles for Java Report, Dr Dobbs Journal, Java Developers Journal, and Web Techniques He has been a technical reviewer of multiple books, including Enterprise Java Beans by Valesky, Java How to Program by Dietel and Dietel, Professional JSP by Wrox, and Java Language API Superbible from the Waite Group all the way back in 1996 iv About the Authors Walter Hurst is the chief technology officer and founder of Wakesoft He is widely recognized as a leader in the design and implementation of large-scale distributed enterprise applications At Wakesoft, Walter was the product architect and author before becoming more involved in company strategy and industry leadership He is a frequent speaker at conferences and often writes for technical publications During his career he has been involved in the design, architecture, and implementation of distributed business systems for many Fortune 1000 companies as an independent consultant and also, while at Xpedior and Andersen Consulting, Walter received a B.S in computer engineering from the University of Michigan When he needs a break from technology, Walter volunteers as a scuba diver for the Steinhart Aquarium in San Francisco, where he cleans the shark tank Ashish Jain is an enterprise consultant/architect with over ten years of IT experience He currently works for BEA Systems Professional Services In this capacity, Ashish assists BEA customers in designing and implementing their e-business strategies using solutions based on J2EE He holds several industry certifications from SUN and BEA He is an active member of local J2EE-user groups and a board member of the Denver BEA-user group He holds a degree in electronics engineering from BITS Pilani, India Mark Little is Head of Transactions Technology for Arjuna Technologies Limited, a company that spun off from Hewlett-Packard to concentrate on developing transactions technologies for J2EE and Web services Prior to this, Mark was a distinguished engineer/architect in HP’s Arjuna Labs in England, where he led the HP Transaction Service and HP Web Services Transaction teams He is one of the primary authors of the OMG Activity Service Specification He is a member of the expert group for the work in J2EE: JSR 95 and JSR 117, and is the specification lead for JSR 156 (Java API for XML Transactions) Mark is active on the OTS Revision Task Force and the OASIS Business Transactions Protocol specification He is the coauthor of an upcoming book, Transaction and Java for Systems Professionals (Prentice Hall) He has been published in many industry magazines, including Doctor Dobbs, The Java Developers Journal, the Web Services Journal, Developer.com, and Application Development Advisor Mark holds a Ph.D in computer science from the University of Newcastle Vaidyanathan Nagarajan, a.k.a Nathan, is the coauthor of a recent book, Xquery — Kick Start (Sams Publishing) He coauthored Professional EJB for Wrox in summer of 2001 He has seven years of experience in information technology Prior to joining Hartford Life Insurance as an enterprise developer, he worked as a consultant to Netscape Professional Services He has an M.B.A in General Management from a leading business school in the New England area He is a former student of the Indian Institute of Technology, Mumbai, India His main interests include programming in Java, robotics using Lego Mindstorms, writing, reading, and cartooning If he is not thinking about design patterns or Java, he will be modeling a robot in his robotic lab He can be reached at vnathan@hotmail.com About the Authors Harshad Oak holds a master’s degree in computer management and is a Sun Certified Java Programmer and a Sun Certified Web Component Developer He has been part of several J2EE projects at i-flex Solutions and Cognizant Technology Solutions He is also a regular contributor of articles to developer Web sites like http://www.builder.com Lee Anne Phillips has a long history in computer networking and interface design, having created beaucoup systems-firmware and machine-language hardware-interface routines before the appearance of Java and other sensible tools to relieve the burdens of a suffering humanity She attended the University of California at Berkeley Lee Anne is the author of many books and articles on computer-related subjects, including Special Edition Using XML, Practical HTML 4, and about a fifth of HTML 4.0 Unleashed Professional Reference Edition An extended list may be seen on her Web site: www.leeanne.com v Credits Acquisitions Editor Jim Minatel Vice President and Publisher Joseph B Wikert Project Editors Valerie H Perry Neil Romanosky Mark Enochs Executive Editorial Director Mary Bednarek Technical Editor Kunal Mittal Copy Editor S B Kleinman Editorial Manager Mary Beth Wakefield Vice President & Executive Group Publisher Richard Swadley Vice President and Executive Publisher Bob Ipsen Project Coordinator Kristie Rees Graphics and Production Specialists Beth Brooks Jennifer Click Sean Decker Heather Pope Quality Control Technicians Laura Albert John Greenough Brian H.Walls Media Development Specialist Angela Denny Proofreading and Indexing TECHBOOKS Production Services Foreword S omething about this book needs to be short, so I guess it’s going to have to be the foreword Seriously, though, this is a very good book In fact, it’s the best introduction to J2EE that I’ve seen It’s well written, covering all the information you need to succeed with J2EE And it’s presented in an order that makes sense — the chapters provide an end-to-end overview of J2EE The book starts by showing you how to build the frontend of your application, then describes your connectivity options, then shows you how to build your business logic using Enterprise JavaBeans (EJB), and finally explains how to connect to the backend databases In other words, this book is architecturally layered Why should you read this book? First, because the authors know what they’re talking about and can explain it in ways that you can understand Second, because it really does cover the fundamentals of J2EE incredibly well The first five parts of this book are oriented toward people learning to work with J2EE technology, and in my opinion they an incredibly good job of explaining exactly what you need to know Third, because the book goes beyond J2EE Part VI is a great overview of using Web services with J2EE, a critical issue most developers need to understand Part VII is a great overview of common J2EE patterns, and Part VIII covers such important topics as performance and frameworks In many ways this book is a “one-stop shop” for J2EE information In the end the thing that I like most about this book is that it’s practical Yes, it’s pretty darn big, but as a result it provides a significant amount of real-world advice Isn’t that what good books are supposed to do? Scott W Ambler Senior consultant, Ronin International, Inc (http://www.ronin-intl.com) Author, Agile Modeling, Agile Database Techniques Coauthor, Mastering EJB 2/e 962 Index ✦ P patterns (continued) proxy, 769 related patterns defined, 731 results defined, 731 router, 730, 736–740 sample code defined, 731 service-activator, 797, 805–811 service-locator, 764, 781–785 servlet filters for Wrapper pattern, 101–102 session, 730, 731–736 session-authenticator, 764, 789–794 session-facade, 764, 773–777 stateless-service-provider, 764, 794–796 strategies defined, 731 Struts framework, 827–828 transfer-object, 797, 811–816 value-object, 764, 769–773 view-helper, 730, 750–754 Web-tier model, 730 #PCDATA keyword, 25 percent sign (%) for JSP comments (