Welcome to the first installment of Journeyman J2EE. I'm honored to present this new bi-monthly column of ruminations and reactions as I, like so many of you, make my foray through the vast world of J2EE application development and deployment. But this isn't intended just for newbie J2EE developers. On the contrary, I hope to also share tips and techniques of value to experienced JSP/servlet developers.
The definition of a journeyman is "a competent and reliable performer or exponent." To me, it connotes a day-to-day working craftsman.
Does this describe you? Are you like a journeyman infielder in professional baseball (apologies to international readers)? It's not that a journeyman isn't valuable to the team. Journeymen contribute in a professional, competent, workman-like way, and strive to improve their abilities and refine their craft.
That's the goal of the Journeyman column, which began nearly two years ago as a monthly column in our sister magazine, ColdFusion Developer's Journal: to share tips and techniques that aren't quite advanced, but aren't quite beginner either. With four years as a Web application developer (mostly in ColdFusion), trainer, and writer, and 20 years of IT experience, I hope I'm in a position to discover and share useful observations.
Filling a Gap for Both Experienced
and Newcomer J2EE Developers
Some of you may scoff at my mentioning experience in ColdFusion (which is really a shame, since it's often unfairly maligned). The bottom line is that it's a Web application development platform, just as ASP, PHP, and J2EE are. Admittedly, each has its own distinct flavor and unique capabilities.
But when it comes down to it, there really are quite a lot of similarities among all Web application development platforms: HTTP processing, opportunities for client enhancement, clever form-processing tricks, effective database integration, session processing, and lots more.
As I move into the J2EE arena I notice that quite a few techniques and approaches used by developers on those other platforms haven't made it into the toolbag of many J2EE developers. Perhaps it's because the focus for them has been more on simply getting into Web apps as they move from Java client to server development. But we who develop on those other platforms have been doing Web apps for years, playing all manner of tricks with browsers, sharing data between Web sites, and more. Maybe these experiences can be of value to J2EE developers.
So on the one hand, the column will speak to experienced J2EE developers by offering Web application development ideas that may be new to them.
On the other hand, if you're making the leap from another Web app development platform to J2EE, you have an entirely separate set of problems, not the least of which is coping with learning Java in general, and then all the capabilities of J2EE. You not only need to figure out how to apply your previous Web app experience in this new platform, but you need to deal with peculiarities and unique features enabled in J2EE.
The problem is, where do you begin? Do you start with a J2EE book? A JSP book? A servlet or EJB book? You'd better be careful. Almost all of these will presume you already understand Java. This may have made sense previously in that most writers were speaking to the vast army of Java developers making the move to the server-side, or enterprise, platform. But it leaves many newcomers to both Java and J2EE unable to start with those books.
Many introductory Java books, articles, and classes, on the other hand, presume that the reader is coming from a C or even C++ background (or no programming background at all). Again, that may have been a reasonable marketing decision in the early days of the transition to Java, but as more Web app developers with ASP (VBScript) or ColdFusion (CFML) make the transition, they're often hard-pressed to appreciate the analogies and references to how much better (or simply different) Java is than C and C++.
A particularly strong example of this is the almost paltry coverage of objects, object-oriented design, and object-oriented programming in many introductory texts. Often it's given just a chapter (and in some books, just a section), which does a terrible disservice to newcomers to Java, though it may have made sense speaking to C++ programmers.
Another dilemma is that many of the resources available presume that (1) all those new to Java want to learn about building Web clients, and (2) all those new to J2EE are experienced Java developers "moving up" but lacking Web app experience. It can be a frustrating experience for many.
So this column will also speak to new J2EE developers who have previous Web app development experience, helping them make the transition to the powerful and incredibly rich Java and J2EE platforms.
J2EE Newcomer's Introductory Java Library
Still, there's no getting around the fact that the first step is to learn the language and platform. Some may suggest that you can create a JSP page without knowing Java, and that may be true in the most generous sense, but you won't get far beyond the most trivial examples without a solid grounding in the fundamentals of Java.
Let me take a moment and commend a few highly regarded introductory books: Ivor Horton's Beginning Java 2, Cay Horstmann and Gary Cornell's Core Java 2, Bruce Eckel's Thinking in Java, and one you may not yet have heard of, Jacquie Barker's Beginning Java Objects.
Beginning Java 2 gets nearly unanimous praise for its lucid introduction to Java. More than a third of the book (seven out of 20 chapters) focuses on client-side application development, but the first several chapters are an excellent introduction to core Java.
This of course leads nicely into the book of the same name, Core Java 2. Again, it's roundly applauded as a seminal work for its encyclopedic yet approachable coverage - and indeed worthy of the praise - but it, too, is heavily laden with client-side development chapters (four out of 12).
Yet another foundational book is Thinking in Java (2nd ed.), a tour de force introduction to Java as not just another language but as a new way to design and code applications (with only one of the 15 chapters - appropriately late in the book - covering applet development).
I highly recommend his Hands-on Java CD-ROM as well, which parallels the book and offers a multimedia version of his seminar of the same name. If you can get a portable MP3 player (there are some that will play straight from the CD, or you can download files to it), you can listen to it on the train, during a workout, in the car, or wherever, and hear it over and over. It's a wonderful way to get grounded in the fundamentals (and some of the dark corners) of Java.
Finally, the most recent of these is the one that I feel does the best job of filling in the gaps left by the others in their coverage of objects and object-oriented programming: Beginning Java Objects. While some have said it's not the first book they'd recommend for newcomers to Java, I wonder if they're bringing a bias of already understanding objects. I found Barker's book wonderfully refreshing and straightforward on that subject, considering the alternatives, while also serving as an adequate introduction to the Java language.
Indeed, all these books are excellent resources for even the more experienced programmer. As Barker points out, it's easy to write Java code that doesn't truly leverage objects. It's a terribly ineffective way to do so, but entirely possible. I even recommend it to experienced Java developers (all but the most experienced or cynical).
Of course, these aren't the only Java introductory books (not even a fraction of the total number), nor are they necessarily the best for everyone. This is just one person's opinion (backed by similarly favorable reviews and awards on many sites). Before I leave the subject of getting a good head start on Java, there are several Web sites you can refer to (perhaps the most prominent being http://java.sun.com), and magazines (including the one you hold in your hand) as well. Be sure to ask your cohorts for their recommendations. There are too many to list.
Getting Started with J2EE: Resources
Now that you have a few resources to get you off the ground with Java, or if you're already comfortable with the core language, the next step is to become familiar (even intimate) with the J2EE platform. Again, there are several resources for this, including books, Web sites, and of course the magazine you're reading, among others.
As mentioned before, http://java.sun.com may be the best place to get started, specifically http://java.sun.com/j2ee/. This incredibly rich and deep site has a seeming never-ending supply of resources for the J2EE developer, including the J2EE Tutorial, Blueprints, case studies, tools, and white papers.
Other prominent portal (information) sites include www.theserverside.com, www.jguru.com, www.jspinsider.com, and more. Even if you're using a competing Java application server, you should also consider sites such as www.ibm.com/developerworks/ and http://developer.bea.com. These offer documentation, tools, newsgroups, source code, articles, user groups, and many other resources.
As for books, there are many popular ones from a variety of standpoints, including: Designing Enterprise Applications with the Java 2 Platform, Enterprise Edition (the printed version of the J2EE Blueprints)
Core Servlets and JavaServer Pages (Marty Hall)
Professional Java Server Programming J2EE Edition (Wrox Press)
There are many more, including books on EJBs, servlets, and JSPs. Ask your colleagues, or visit portal sites and book review sites for more opinions. Just be aware that almost all of these books presume you have Java experience. And even then they may presume you don't have prior Web application development experience, so be prepared for some review-level material on those aspects (such as, "A form can have 5 kinds of input controls...").
Finally, as you embark on your own journey into the world of Java and J2EE, you may also need to learn about such topics as UML (and object-oriented design in general), patterns (both general design and J2EE), and many more related topics that separate the newcomer from the professional.
Clearly, for those making the transition from Web application development in ASP/CF/PHP, and others, there's a need for a book that meets both the foundational needs of learning Java (without too much client-side focus) while also offering foundational J2EE material (without presuming Java experience or repeating already understood Web app development fundamentals). I hope someone out there is listening and realizes there's a market. I've considered it myself, but I'm busy enough for now! I hope you'll join me in future installments of Journeyman J2EE.
Charles Arehart is a 20-year IT veteran with experience
spanning a range of technologies, including very large-scale
database systems. For the past four years, he's been an active trainer, writer, and consultant in enterprise Web application development.