Computacion E Informatica

The J2EETM Tutorial
Stephanie Bodoff Dale Green Eric Jendrock Monica Pawlan Beth Stearns

Copyright © 2001 by Sun Microsystems, Inc. 901 San Antonio Road, Palo Alto, California 94303 U.S.A. All rights reserved. RESTRICTED RIGHTS LEGEND: Use, duplication, or disclosure by the United States Government is subject to the restrictions set forth in DFARS 252.227-7013(c)(1)(iii) and FAR 52.227-19.The release described in this book may be protected by one or more U.S. patents, foreign patents, or pending applications. Sun, Sun Microsystems, Sun Microsystems Computer Corporation, the Sun logo, the Sun Microsystems Computer Corporation logo, Java, JavaSoft, Java Software, JavaScript, JDBC, JDBC Compliant, JavaOS, JavaBeans, Enterprise JavaBeans, JavaServer Pages, J2EE, J2SE, JavaMail, JavaNaming and Directory Interface, EJB, and JSP are trademarks or registered trademarks of Sun Microsystems, Inc. UNIX® is a registered trademark in the United States and other countries, exclusively licensed through X/Open Company, Ltd. All other product names mentioned herein are the trademarks of their respective owners. THIS PUBLICATION IS PROVIDED “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHEREXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. THIS PUBLICATION COULD INCLUDE TECHNICAL INACCURACIES OR TYPOGRAPHICAL ERRORS. CHANGES ARE PERIODICALLY ADDED TO THE INFORMATION HEREIN; THESE CHANGES WILL BE INCORPORATED IN NEW EDITIONS OF THE PUBLICATION. SUN MICROSYSTEMS, INC. MAY MAKE IMPROVEMENTSAND/OR CHANGES IN THE PRODUCT(S) AND/OR THE PROGRAM(S) DESCRIBED IN THIS PUBLICATION AT ANY TIME.

Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xxi
Who Should Use This Tutorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxi About the Examples. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xxii Prerequisites for the Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxii Downloading the Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxii How to Build and Run the Examples . . . . . . . . . . . . . . . . . . . . . . . . . xxiii Related Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxiv How toPrint This Tutorial. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxv Typographical Conventions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxv Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxvi

Chapter 1: Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Distributed Multitiered Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J2EE Application Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Client Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Application Clients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Web Browsers . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Applets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . JavaBeans™ Component Architecture . . . . . . . . . . . . . . . . . . . . . J2EE Server Communications. . . . . . . . . . . . . . . . . . . . . . . . . . . . Thin Clients. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . Web Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Business Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Enterprise Information System Tier . . . . . . . . . . . . . . . . . . . . . . . . . . . J2EE Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....