 |
 |
261
263
263
264
264
267
268
269
11.6.1
11.6.2
Monday Morning, 10 A.M. ......................................................
Back at His Desk ....................................................................
269
272
11.7
Documenting, Prototyping, and Stakeholder Buy-In ...........................
272
11.7.1
11.7.2
11.7.3
Documenting ..........................................................................
Stakeholder Buy-In ................................................................
Prototyping .............................................................................
272
274
275
11.8
11.9
Review ................................................................................................ What You Still Don’t Know ..................................................................
276
276
11.10 Resources ..........................................................................................
11.11 Exercises ............................................................................................
276
277
Chapter 12
12.1
12.2
12.3
12.4
12.5
12.6
12.7
12.8
12.9
Analysis and Design: Seeking the Objects ................................
What You Will Learn ...........................................................................
Facing the Blank Page .......................................................................
Using CRC Cards ...............................................................................
Finding the Objects .............................................................................
Finding the Methods and Attributes ....................................................
Essential and Nonessential ................................................................
Analysis Paralysis ...............................................................................
Real Software Engineering .................................................................
Core Classes ......................................................................................
279
279
280
280
280
283
284
287
288
289
12.10 Review ................................................................................................
12.11 What You Still Don’t Know ..................................................................
12.12 Resources ..........................................................................................
12.13 Exercises ............................................................................................
289
289
289
292
Chapter 13
13.1
13.2
13.3
13.4
JUnit: Automating Unit Testing ...................................................
What You Will Learn ...........................................................................
JUnit: Why All the Fuss? ....................................................................
Design Then Test Then Code ............................................................
Installing and Running JUnit ...............................................................
295
295
296
296
297
13.4.1
13.4.2
Downloading and Unzipping .................................................. Using JUnit .............................................................................
299
301
13.5
Writing Test Cases .............................................................................
303
13.5.1
13.5.2
JUnit Assertions .....................................................................
Running a Test Case .............................................................
306
308
13.6
13.7
13.8
13.9
Running Test Suites ...........................................................................
Review ................................................................................................ What You Still Don’t Know ..................................................................
Resources ..........................................................................................
309
312
312
313
13.10 Exercises 313
Chapter 14
14.1
14.2
14.3
14.4
14.5
Storing the Data ............................................................................
What You Will Learn ...........................................................................
Follow the Objects ..............................................................................
Of Persistence ....................................................................................
Thinking of the Future, or Painting in Corners .................................... Oracle, PostgreSQL, MySQL .............................................................
315
315
316
316
316
316
14.5.1
14.5.2
14.5.3
14.5.4
MySQL ...................................................................................
PostgreSQL ...........................................................................
Oracle ....................................................................................
Selection Criteria ....................................................................
317
317
318
318
14.6
14.7
14.8
14.9
Being Self-Contained ..........................................................................
Beyond the Basics .............................................................................. Persistence Is Not the Whole Story ....................................................
Setting Up PostgreSQL for BudgetPro ...............................................
318
319
322
322
14.9.1
14.9.2
14.9.3
14.9.4
Installing PostgreSQL ............................................................
Creating a postgres User .................................................
Creating Our Database ..........................................................
Straight JDBC ........................................................................
322
323
324
325
14.10 Review 325
14.11 | What You Still Don’t Know .................................................................. | 326 |
14.12 | Resources .......................................................................................... | 326 |
14.13 | Exercises ............................................................................................ | 326 |
Chapter 15 | Accessing the Data: An Introduction to JDBC ........................... | 327 |
15.1 | What You Will Learn ........................................................................... | 327 |
15.2 | Introducing JDBC ............................................................................... | 328 |
15.3 | Making Connections ........................................................................... | 329 |
15.3.1 Downloading JDBC for MySQL .............................................. | 332 | |
15.4 | Querying Data .................................................................................... | 332 |
15.5 | Getting Results ................................................................................... | 334 |
15.6 | Updates, Inserts, Deletes ................................................................... | 336 |
15.7 | Review ................................................................................................ | 336 |
15.8 | What You Still Don’t Know .................................................................. | 336 |
15.9 | Resources .......................................................................................... | 337 |
15.10 | Exercises ............................................................................................ | 338 |
PART III | Developing Graphical User Interfaces ................ | 339 |
Chapter 16 | Getting in the Swing of Things: Designing a GUI for BudgetPro ...................................................................................... | 341 |
16.1 | What You Will Learn ........................................................................... | 341 |
16.2 | A Simple Swing Program .................................................................... | 342 |
16.3 | Stompin’ at the Savoy, or The Swing Paradigm ................................. | 343 |
16.4 | Slow, Slow, Quick-Quick, Slow: The Basic Swing Objects ................. | 345 |
16.5 | Layout Managers ................................................................................ | 347 |
16.6 | Beyond Arthur Murray: Actions, Listeners, Events ............................. | 348 |
16.7 | Getting Down to Cases: Designing a GUI for BudgetPro ................... | 348 |
16.7.1 Overview ................................................................................ | 350 | |
16.7.2 Creating Pieces ...................................................................... | 352 | |
16.8 | Review ................................................................................................ | 373 |
16.9 | What You Still Don’t Know .................................................................. | 374 |
16.10 | Resources .......................................................................................... | 375 |
16.11 | Exercises ............................................................................................ | 375 |
Chapter 17
17.1
17.2
Other Ways: Alternatives to Swing .............................................
What You Will Learn ...........................................................................
The IBM SWT Toolkit .........................................................................
377
377
378
17.2.1 | Another GUI Toolkit. Why? .................................................... | 378 | |
17.2.2 | Duplicated Effort. Why Cover It? ............................................ | 379 | |
17.2.3 | Portability: Better and Worse .................................................. | 380 | |
17.2.4 | The Rest of the Chapter ......................................................... | 380 | |
17.2.5 | SWT: Close to the Metal ........................................................ | 380 | |
17.2.6 | “Hello, world” SWT Style ........................................................ | 381 | |
17.3 | Porting | BudgetPro to SWT ................................................................. | 384 |
17.3.1 | Step 1: Convert the Class Members ...................................... | 387 | |
17.3.2 | Step 2: Converting the main() Method .............................. | 389 | |
17.3.3 | Step 3: Converting the GUI build() and init() Methods ................................................................................. | 391 | |
17.3.4 | Completing the Conversion of the BudgetPro Class ........ | 394 | |
17.3.5 | Completing the Conversion of the Application ....................... | 395 | |
17.3.6 | Closing Thoughts ................................................................... | 395 |
17.4
17.5
17.6
17.7
17.8
SWT and gcj ......................................................................................
Review ................................................................................................ What You Still Don’t Know ..................................................................
Resources ..........................................................................................
Exercises ............................................................................................
396
398
398
398
399
PART IV | Developing Web Interfaces .................................. | 401 |
Chapter 18 | Servlets: Java Pressed into Service ............................................ | 403 |
18.1 | What You Will Learn ........................................................................... | 403 |
18.2 | Servlets: Program-Centric Server-Side Documents ........................... | 404 |
18.3 | Perspective ......................................................................................... | 405 |
18.4 | How to Write a Servlet ........................................................................ | 407 |
18.5 | Input, Output ....................................................................................... | 411 |
18.6 | Matters of State: Cookies, Hidden Variables, and the Dreaded “Back” Button ...................................................................................... | 413 |
18.6.1 Cookies .................................................................................. | 414 | |
18.7 | Designing a BudgetPro Servlet .......................................................... | 416 |
18.7.1
18.7.2
Prototype ................................................................................
Design ....................................................................................
416
417
18.8
18.9
Review ................................................................................................ What You Still Don’t Know ..................................................................
420
420
18.10 Resources ..........................................................................................
18.11 Exercises ............................................................................................
421
421
Chapter 19
19.1
19.2
19.3
JSP: Servlets Turned Inside Out .................................................
What You Will Learn ...........................................................................
Servlets Turned Inside Out: JSP ........................................................
How to Write a JSP Application ..........................................................
423
424
424
426
19.3.1
19.3.2
19.3.3
19.3.4
19.3.5
19.3.6
19.3.7
Scriptlet ..................................................................................
Declaration .............................................................................
Expression .............................................................................
Directive .................................................................................
New Syntax ............................................................................
JavaBeans in JSP ..................................................................
Tag Libraries ..........................................................................
427
429
430
431
434
434
437
19.4
19.5
19.6
19.7
19.8
Chapter 20
20.1
20.2
20.3
Using JSP with BudgetPro ................................................................. Review ................................................................................................ What You Still Don’t Know ..................................................................
Resources ..........................................................................................
Exercises ............................................................................................
Open Source Web Application Servers ......................................
What You Will Learn ...........................................................................
Downloading JBoss ............................................................................
Be an Enabler, or “Let’s Be Codependent!” ........................................
438
439
440
440
441
443
443
444
444
20.3.1
20.3.2
Nonroot-Installed Software ....................................................
Finer Grained Control ............................................................
445
450
20.4
20.5
Installing JBoss ...................................................................................
Things That Make It Go ......................................................................
450
451
20.5.1
20.5.2
20.5.3
20.5.4
System V Init System .............................................................
RedHat/Fedora chkconfig ....................................................
Other Distributions .................................................................
IDE Integration .......................................................................
451
458
463
464
xviii Contents
20.6
20.7
20.8
20.9
Disposition of Forces ..........................................................................
Apache Geronimo ...............................................................................
Installing Geronimo .............................................................................
Running the Geronimo Server ............................................................
464
464
467
468
20.10 Review ................................................................................................
20.11 What You Still Don’t Know ..................................................................
20.12 Resources ..........................................................................................
468
469
469
PART V | Developing Enterprise Scale Software ............... | 471 |
Chapter 21 | Introduction to Enterprise JavaBeans ........................................ | 473 |
21.1 | What You Will Learn ........................................................................... | 473 |
21.2 | Expanding to EJBs ............................................................................. | 473 |
21.2.1 EJB Concepts ........................................................................ | 474 | |
21.2.2 Bean Types ............................................................................ | 477 | |
21.2.3 Under the Hood ...................................................................... | 482 | |
21.3 | What’s in a Name? An Introduction to JNDI ....................................... | 482 |
21.3.1 Naming and Directory System Concepts ............................... | 482 | |
21.3.2 Common Directory Services .................................................. | 484 | |
21.3.3 Putting a Face to a Name: JNDI ............................................ | 487 | |
21.3.4 Using JNDI with JBoss ........................................................... | 491 | |
21.4 | Review ................................................................................................ | 491 |
21.5 | What You Still Don’t Know .................................................................. | 492 |
21.6 | Resources .......................................................................................... | 492 |
Chapter 22 | Building an EJB ............................................................................. | 493 |
22.1 | What You Will Learn ........................................................................... | 493 |
22.2 | EJBs: You Don’t Know Beans? .......................................................... | 493 |
22.2.1 SessionBean .................................................................... | 495 | |
22.2.2 EJBObject ......................................................................... | 497 | |
22.2.3 EJBHome .............................................................................. | 498 | |
22.2.4 Summarizing the Pieces ........................................................ | 499 | |
22.2.5 EJBLocalHome and EJBLocalObject ...................... | 499 | |
22.2.6 Compiling Your Beans ........................................................... | 501 | |
22.3 | Review ................................................................................................ | 502 |
22.4 | What You Still Don’t Know .................................................................. | 502 |
22.5 | Resources .......................................................................................... | 503 |
Chapter 23 | Deploying EJBs ............................................................................. | 505 |
23.1 | What You Will Learn ........................................................................... | 505 |
23.2 | Lend Me Your EAR: Enterprise Packaging and Deployment ............. | 506 |
23.2.1 What’s in an EJB-JAR File ..................................................... | 508 | |
23.2.2 Using Our Bean ..................................................................... | 511 | |
23.2.3 Packaging the Servlet ............................................................ | 512 | |
23.3 | Deploying the EAR ............................................................................. | 514 |
23.3.1 JBoss ..................................................................................... | 515 | |
23.3.2 Geronimo ............................................................................... | 515 | |
23.4 | Maintaining a Distributed Application ................................................. | 516 |
23.4.1 Ant and CVS .......................................................................... | 516 | |
23.4.2 XDoclet .................................................................................. | 517 | |
23.5 | Abstracting Legacy Applications ......................................................... | 518 |
23.6 | Review ................................................................................................ | 518 |
23.7 | What You Still Don’t Know .................................................................. | 519 |
23.8 | Resources .......................................................................................... | 519 |
Chapter 24 | Parting Shots ................................................................................. | 521 |
24.1 | The Future’s So Bright, I Squint and Look Confused ......................... | 521 |
24.2 | Our Book Is Yours .............................................................................. | 522 |
24.3 | Came the Revolution .......................................................................... | 522 |
24.4 | What You Still Don’t Know .................................................................. | 523 |
24.5 | Resources .......................................................................................... | 523 |
Appendix A | ASCII Chart .................................................................................... | 525 |
Appendix B | A Java Swing GUI for BudgetPro ................................................ | 527 |
Appendix C | GNU General Public License ........................................................ | 539 |
Index 549
Preface
JAVA AND LINUX
Why another book on Java? Why a book on Java and Linux? Isn’t Java a plat- form-independent system? Aren’t there enough books on Java? Can’t I learn everything I need to know from the Web?
No doubt, there are a host of Java books on the market. We didn’t wake up one morning and say, “You know what the world really needs? Another book about Java!” No. What we realized was that there are a couple of “holes” in the Java book market.
First, Linux as a development platform and deployment platform for Java applications has been largely ignored. This is despite the fact that the *nix platform (meaning all UNIX and UNIX-like systems, Linux included) has long been recognized as one of the most programmer-friendly platforms in existence. Those few resources for Java on Linux that exist emphasize tools to the exclu- sion of the Java language and APIs.
Second, books on the Java language and APIs have focused on pedagogical examples that serve to illustrate the details of the language and its libraries, but very few of these examples are in themselves practically useful, and they tend
xxi
to deal only with the issues of writing programs, and not at all with deploying and maintaining them. Anyone who has worked on a major software project, especially a software project that is developed and deployed in a business for a business, knows that designing and coding are only about half of the work in- volved. Yes, writing Java code is only slightly affected by the development and the deployment platform, but the process of releasing and maintaining such applications is significantly different between platforms.
To address these missing pieces, we decided to cover development and deployment of a Java application that has command-line, GUI, servlet, and enterprise components on a Linux platform. We’re writing the guide book we wish we had had when we started writing and deploying Java applications on Linux. We’re going to show you a simplistic enterprise application, “from cradle to grave,” but along the way cover issues of design process, production environ- ment, setup, administration, and maintenance that few books bother to cover.1 If you are considering buying this book and you are wondering if there is
any information in here that you can’t get for free on the Web, then, no. There is not. In fact, there is little information in any Java or Linux book that is not available for free on the Internet. In fact, in each of our chapters we will tell you where on the Web to find virtually all of the information we present, and then some. And yet books continue to sell, and we have the chutzpah to ask you to buy the book. The reason is that Web information is scattered, unorga- nized, and of highly variable quality. We will be trying to bring all the relevant information together in this book, in a clearly organized manner (and, we would like to believe, at an acceptably high level of quality). We think that has value.
Also, this book is part of the Bruce Perens’ Open Source Series. This book is part of the Web literature. And you may freely read it and use it on the Web. We hope this book will be one of those you use on the Web and buy on paper. We don’t know about you, but we like to use Web books for reference, but for reading, we like books. We own at least three books that are available for free on the Web: Thinking in C++, Thinking in Java, and O’Reilly’s Docbook: The Definitive Guide. We hope that open publishing will be the new model.
1. This is not to say this book is without purely pedagogical examples. Especially in Part I we make use of your typical “throwaway” examples and single classes. To try to illustrate the basics with a complete application would obscure and confuse the points being illustrated.
FREE SOFTWARE AND JAVA
GNU/Linux2 is Free Software. It is Open Source. I don’t even want to start the debate on what each term means and which one is “right.” One of the two authors of this book is a Free Software advocate, and the other is of a purely laissez-faire attitude towards the question (we won’t tell you which, although we invite you to guess). But even with a deliberate decision to cease-fire, the question remains: Is Java Open Source or Free Software?
The answer is mixed. Neither Sun’s nor IBM’s Java implementations are Open Source or Free Software. You may download and use them for free, but you do not have the source code to them, nor do you have the right to make modifications to them.3 This book will cover the GNU Compiler for Java, which compiles Java source code to native machine code. The GNU Compiler for Java (gcj) is both Open Source and Free Software. It is, however, supporting differing levels of the Java APIs (some packages are current, some are back at
1.1.x levels) and does not fully support the AWT or Swing GUIs.
However, none of this means that you cannot write your own Java pro- grams and release them under a Free Software or Open Source license. So you can certainly develop Free Software in Java. Staunch Free Software partisans (such as Richard Stallman and the Free Software Foundation) would question the wisdom of doing so. Their argument would be that a Free Software product that depends on non-Free tools isn’t really Free Software, since to compile, use, or modify it, you need to make use of a proprietary tool.
There is more than one effort to produce a Free Software Java runtime implementation. None of them is “ready for prime time.” It would, in our opinion, be a very good thing for Sun to release their SDK and Java Virtual Machine as Free Software. But so far, they have steadily resisted calls to do so.
2. This is the only time we will refer to it as “GNU/Linux.” See Section 7.3 for the story of why GNU/Linux is the preferred name of some. We understand Stallman and the FSF’s posi- tion, but “Linux” is much easier on the eyes and ears than “GNU/Linux.” And that, not prin- ciple, is how names and words go into the language. For better or for worse, “Linux” is the name of the operating system.
3. As we write this, a very public discussion is taking place between Sun, IBM, and Eric Ray- mond, founder of the Open Source Initiative, about opening Java under some sort of open source license. At this time, no one knows how this will turn out, but it is possible that Java will be Free Software in the future.
The fact, however, that two distinct vendors (Sun and IBM) produce ef- fectively interchangeable development and runtime environments reduces some of the risk that you face when you select a platform available only from a single vendor who does not provide source code.
So, to put the case firmly: Java is free for use, but it is certainly not Free Software as defined in The GNU Manifesto 4 or the GNU General Public Li- cense.5 This is a political and philosophical issue of interest only to those aforementioned Free Software partisans. For the rest of us, this has no bearing on Java’s technical or business merits. As for us, obviously we like the language or we wouldn’t be writing about it.
YOU CAN HELP!
This book is part of the Bruce Perens’ Open Source Series. Shortly after this book is published in dead-tree form, it will be on the Web,6 free for use, redis- tribution, and modification in compliance with the terms of the Open Publica- tion License,7 with no options taken. You can immediately create your own version as permitted in that license.
Naturally enough, we plan to maintain our “official” version of the online book, so we encourage you to send suggestions, corrections, extensions, com- ments, and ideas to us. Please send any such to javalinux@multitool.net and we will try to keep our little tome up-to-date so it continues to serve the needs of the Java and Linux development communities.
ACKNOWLEDGMENTS
First off, we naturally wish to thank Mark L. Taub, our acquisitions editor at Prentice Hall PTR, for believing in the book and in open publishing as the way to put it out there. We also want to thank Bruce Perens for lending his name and powers of persuasion to open-content publishing through the Prentice Hall PTR Bruce Peren’s Open Source Series. Thanks, too, to Patrick Cash-Peterson
4. http://www.gnu.org/gnu/manifesto.php
5. http://www.gnu.org/copyleft/gpl.php
6. http://www.javalinuxbook.com/
7. http://www.opencontent.org/openpub/
and Tyrrell Albaugh, who worked as our in-house production contacts, for all the behind-the-scenes work they did, including overseeing the cover.
In more direct terms of content, we owe major thanks to Kirk Vogen of IBM Consulting in Minneapolis for his article on using SWT with gcj, and for his kind help in allowing us to use the ideas he first presented in his IBM developerWorks articles. In more direct terms of content, we owe major thanks to: Kirk Vogen of IBM Consulting in Minneapolis for his article on using SWT with gcj, and for his kind help in allowing us to use ideas he first presented in his IBM developerWorks articles; and to Deepak Kumar8 for graciously allow- ing us to base our build.xml file for EJBs off of a version that he wrote.
Thanks, too, to Andrew Albing for his help in drawing some of our dia- grams, and to George Logajan and to Andy Miller for sharing their insights on the more intricate details of Swing.
We also wish to express our great indebtedness to our technical reviewers, especially Andrew Hayes, Steve Huseth, and Dan Moore. A very large thank- you is also due to Alina Kirsanova whose eye for detail, endless patience, and tenacity, and overall talent with proofing, layout, and more added so much refinement and improvement to the book. We are greatful for all their contri- butions. Any errors or omissions in this text are our fault and certainly not theirs. The book is much stronger for all their efforts.
There are likely many more people we ought to thank, especially those at Prentice Hall PTR, whose names and contributions we may never know, but we do know that this was an effort of many more people than just the authors, and we are grateful to them all.
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