Top-ranking Software Development Expert and Java Authority
This week, Stephen
Ibaraki, I.S.P., has an exclusive interview with distinguished
author, software development and Java expert, Alan Moffet.
Alan is a consultant with
over 20 years of experience in software development and management.
He specializes in software architecture and design, and development
practice. His work has focused on applying emerging technologies,
updating legacy systems, and improving organizational effectiveness.
His programming experience includes a variety of systems and
programming languages. He began to work with Java professionally
while it was a beta product and continues to follow its development
and use it in his projects. He is a member of the JCP.
Alan has been active in
programming since the days of the Mark 8 (Radio Electronics, July
1974) and progressed through the "classics" - SWTP 6800, H-8, Z-100
and finally the PC. He started programming professionally in 1985
when he began writing diagnostics for hardware that he was
responsible for repairing. In 1991, he joined BNR, the R&D division
of Nortel. There, he began using Java in 1995 for some projects that
leveraged Java's built-in support for networking - including code
mobility. His group was among the first at Nortel to embrace Java.
Although he also uses
other languages and platforms to perform his work, his interest in
Java continues. Besides the widely regarded recent offering, “SAMS
Teach Yourself JavaServer Pages 2.0 with Apache Tomcat in 24 hours,”
he has also contributed to Java P2P Unleashed. In addition, he has
served as a technical editor for XML Unleashed 2nd Edition, SE Using
Enterprise JavaBeans 2.0, SE Using Java 2 Enterprise Edition, SE
Using JSP and Servlets, SE Using Java 2 Standard Edition, SE Using
XSLT, Java APIs for XML, and Windows Telephony Programming.
Q: Alan, you have such a
considerable and proven background in software development, Java,
and long-history of successes in computing. We are most fortunate to
interview you--thank you!
A: Thank you. I
appreciate the opportunity.
Q: You were there when
computers first came out in kit form and progressed to the
PC--profile your early days working with the Mark 8, SWTP 6800, H-8,
Z-100, and PC. Describe your experiences.
A: I’m grateful to have
had the opportunity to work with computers through the evolution of
the personal computer. It’s been an amazing journey. The first
computers I worked with were programmed using your fingers to input
machine code with toggle switches. Light Emitting Diodes provided
the output, although clever programmers could also use nearby radios
as another output device, since the early machines interfered badly
with their reception. Writing loops, you could play songs. Memory
use was limited to a few kilobytes because that was all the machines
had. Once you powered down, everything was lost – there were no
inexpensive storage devices then. However, personal computers
progressed rapidly. It wasn’t long before you could use a basic
operating system, a keyboard and monitor and could save your work to
cassette tapes and eventually to floppy and hard disks. I’m not
nostalgic for those days, but the experience of working on
home-built equipment with limited resources was very valuable. I
also appreciate the pioneering.
Q: What was it like to
program in the 1970s’ through to the 80s’?
A: First, I need to
mention that I essentially grew up with the microprocessor. I didn’t
work with mainframes or larger systems until later in my profession.
So, while there was opportunity to work with mature operating
systems and programming languages during this time, my experience
was limited to what became available on the personal computer, or on
smaller systems like the PDP-11.
Most of the programming
that I did at that time worked in concert with hardware. It was in
assembler or C. Programming required a deep understanding of the
hardware - the applications themselves were usually architecturally
simple. Because of the limited resources, you were careful about
your design – making certain that you did not waste memory or CPU
It was a time of rapid
change - The spirit of invention was everywhere.
Microprocessors and other
logic advanced quickly. Personal computers multiplied as companies
and hobbyists built upon new technology. Personal operating systems
eventually abstracted some of the functions away from the hardware
and the tools became much better. Platforms stabilized. Gradually, I
could stop thinking about how to lay software on top of a machine
and focus on the structure of the software itself. Languages like
C++ and Smalltalk made programming particularly enjoyable. I think
that I was fortunate to be able to watch and participate in the
growth of the personal computer.
Q: Describe your
experiences at Nortel.
A: Nortel is one of the
favorite places I have worked at. The company invested heavily in
its employees by providing opportunities to grow. I participated in
many exciting projects and worked with some great people.
I worked for BNR (or Bell
Northern Research), which was the research and development arm of
Nortel. In particular, I worked with a digital PBX. It was an
incredible piece of machinery with 25-30 million lines of code and
thousands of developers. The breadth of the system provided a
never-ending playground for engineering. One week, I would write a
new random-number generator for the OS and the next investigating
problems within a compiler.
Nortel provided training
in many areas and often had instructors or lecturers who were
inspiring. I was taught Smalltalk by Graham Glass (Formerly of
ObjectSpace and now of The Mind Electric), and listened to Grady
Booch lecture on design and methodologies. I was able to parlay my
education into my work. After finishing a government contract, my
group and I explored technologies that might be useful for
application in the PBX. We were particularly excited about the
possibilities afforded by Java, which was in Alpha testing at the
Q: Detail how Java
programming has progressed from the mid-90s’ to the present.
A: There’s much more to
learn about now! The release of Java, along with the creation of the
World-Wide-Web, inspired thinking about distributed applications.
With applets, you could build competent “light-weight” interfaces to
back-end applications. With a little understanding about
class-loaders and networking, you could build applications that were
easily distributed. The language was easy to learn and forgiving –
we could create a prototype in a fraction of the time it took to
develop the same prototype using X-Windows or Microsoft Windows –
and it ran on either platform (although applets were not as portable
as you would have liked).
Obviously, the platforms
and technologies that exist today did not exist then. Today, the
platforms and technologies that make up Java are comprehensive and
mature. The patterns and architectures of systems are well defined
and broadly understood. Collectively, they make it possible to
easily create sophisticated and robust applications of all types.
Q: Your recent book in
JavaServer Pages is garnering considerable attention. However, first
can you provide ten tips from your other books?
A: That’s a tall order.
I’ve also co-authored a book on P2P programming and worked on a
number of books for other authors as a technical or developmental
editor. The topics vary widely. In fact, people often seem to wonder
how I became “well rounded,” yet have also have depth. What if I
offered a few tips about that?
1) Love what you are
doing. It’s easier to spend time doing something you like. And it
takes time and effort to do anything well.
2) Learn what you are
good at. Chances are that you like to do this also, since you
probably enjoy the satisfaction of a well-done job. You’ll also
stumble across the things you’re not very good at. You can decide to
avoid doing this kind of work, or to focus on improving your
3) Align your talents and
interests with your work. Good managers want to use their resources
effectively and you can practice while you work.
4) Become a mentor, or
find a mentor. I’m a better student of a topic if I’m teaching it.
First, it has to make sense to me before I can help another. Second,
repeating something is practice. Allowing somebody else to be a
mentor helps them sharpen their own skills, brings you up to speed
quickly and helps you avoid the difficult spots on the path to
expertise. A good book can help you by providing information and by
allowing you to learn from the experience of the author.
5) Set goals. Choose
where you will spend your time. I have a regular study schedule for
topics I need to know more about, or feel that I’d like to review.
Your employer may allow you the privilege of studying for a couple
of hours each week at work. After all, they do want qualified
employees who demonstrate great initiative, right? Even if they
can’t afford the time, you may need to spend some of your off-hours
time honing your skills. It’s a competitive marketplace with rapidly
changing technologies – you’re contributing to your own value.
Finally, borrowing from a recent Family Circus comic strip, remember
that “goal” starts with “go.” Accomplish what you set out to do.
Q: Now, let us discuss
your book, which you co-authored, “SAMS Teach Yourself JavaServer
Pages 2.0 in 24 Hours.” Who is the intended audience? Moreover, why
would our readers want to read this book? What is uniquely
compelling about this book?
A: The book is written
for programmers who are somewhat experienced with Java, and would
like to learn how to use JavaServer Pages. If you’ve read about JSPs
elsewhere in the past, you’ll want to read this book for its
practical and in-depth coverage. We have packed a lot of information
into the 24 one-hour sessions without making it difficult to
understand. The book will teach you how to use JSPs in real
applications. Besides introducing the reader to the features of JSP
2.0, it also introduces useful topics such as how to select an
appropriate architecture or how to tune applications for
performance. And it will help you to become a proficient developer
by providing the background necessary to be able to use JSPs
effectively, or debug them when things don’t go as planned.
Q: What new features in
JSP 2.0 make it easy and quick to create Web sites?
A: We were able to put
quite a bit into the book because of the great work that the
specification authors (and everyone else involved in this release)
did to simplify web application development using JSPs. It wasn’t
difficult to explain new features. That might be one of the best
improvements – the “ramp-up” time is significantly smaller. Creating
your own tags has become even simpler (pun intended). Tag files are
great! Of course, EL and Tag libraries will help also. Finally, in
the longer term, these changes, combined with the ability to express
JSPs as XML documents and the improvements made to make it easier to
debug JSPs, will aid productivity and quality as tool developers
release IDEs that are more sophisticated.
Q: Describe working with
the built-in expression language and JSP tag libraries.
A: In the past, it has
been somewhat difficult to keep the functions of your JSPs “pure”.
In other words, if you want to be strict about using JSPs only for
presentation, you would often spend a lot of time developing your
own custom tags. This meant that you had to understand Servlets. You
also needed to know how to work with the underlying mechanisms used
to implement custom tags – which were somewhat troublesome.
Moreover, the design often didn’t accomplish all that you hoped –
the application wasn’t as simple, flexible or maintainable as you
would have liked.
JSP Tag libraries and EL
help considerably. They allow you to focus on presentation in the
JSP. JSP Tag Libraries provide many useful, predefined functions
that you can use to build JSPs using syntax page authors are already
somewhat familiar with. EL is frequently used with Tags to provide
access to expressions involving objects, data, or functions.
The simplicity of EL
makes it easier for page authors to develop sophisticated pages
without having to dive into the complexities associated with
scriptlets. Tool developers will be happier because JSPs can be
completely expressed through tags.
It’s easier to develop
well organized pages that are architecturally consistent. I like
working with these improved features. However, like the developers
of JSTL, I would have liked to have these improvements without
creating two new primitive “languages” (JSTL Core Tags and EL) and
their supporting environment. I expect that we will see continued
improvements in these areas. JSP page authors should not create JSPs
that consist of a significant amount of logic.
Q: How would you go about
debugging your Web applications?
A: As we mention in the
book, debugging web applications can be difficult because there are
many pieces that interact – including application components and
technologies. Well-designed applications are easier to debug. I try
to start out with debugging in mind. For example, when an
application can be divided so that presentation is decoupled from
the underlying data, it’s easier to decide where a problem lies. One
of the techniques that is very useful is good logging. Java 1.4
introduced a logging framework that is good. I prefer to continue to
use Log4J and a supporting tag library. I found that debugging using
logging is enhanced if you are careful about defining the levels of
logging. Putting too much detail into the wrong levels isn’t
helpful. It’s distracting. A full trace isn’t useful when you’re
trying to determine if the user entered something incorrectly.
I’m also careful to write
software that is error-aware. As a language, Java has some great
mechanisms for dealing with problems. Exceptions are very helpful. I
notice that many developers are content to ignore error handling,
partly because Java does such a great job when it lets you know
about an error. I also find that it’s useful to build testing into
components with a framework like JUnit. The Java virtual machine has
always had great support for debugging. With the release of 1.4
there are even better facilities, such as the ability to hot-swap
classes. With JSR-45, you can debug JSPs directly, since there is a
way to correlate byte-codes to JSP source. I use a JPDA capable IDE
with integrated debugging capabilities for difficult problems. With
these, I can examine the state of the application
Q: Discuss using Servlets
and JSP together to build browser-based dynamic applications.
A: JSPs and servlets can
have complimentary roles. I use JSPs where the output is more or
less “templated.” Looking at the source of a JSP, you can
essentially determine what the consumer will see. If I need
different “layouts”, I use different JSPs or compose top level JSPs
from fragments. I use servlets for control, application logic and
other services. In less complicated applications, I use a simple
architecture with only a few tiers. In this case, servlets perform
functions similar to those ordinarily performed by EJBs. I strongly
encourage developers to separate business logic from presentation,
and to use JSPs for presentation. In our book, we provide guidelines
that help you determine which functions should be handled by JSPs or
servlets. We also introduce Model-View-Controller as an example of
how to separate responsibilities. Sun’s “Blueprints” are also a
great resource for the developer.
Q: Comment on including
XML data and XSL stylesheets in JSP applications.
A: It makes perfect sense
to use JSPs to produce structured content using XML. XSLT is a great
tool for transforming documents and can be used to normalize data to
the requirements of the consumer. On the other hand, JSPs should not
parse XML data to build data objects or validate documents. Again,
the role of JSPs should be restricted to rendering data.
Q: Tell us more about
personalizing the users’ experience using cookies.
A: I am impressed with
sites that do a great job personalizing the user’s experience. Each
time I visit Amazon, I am reminded of how effective it can be. They
remember which books I’ve looked at, have suggestions for others
that I might be interested in, allow me to create customized pages
made up of items I want to remember, and even form communities of
interest. Amazon does a great job. Most applications can benefit
from personalization. When used properly, cookies can help an
application become aware of the identity of a user before they
authenticate through another means. It’s easy to work with cookies
only, except as they are used to support sessions. Anything that I
want to remember about the client is stored with the session or in
persistent store. If you choose to store any other information, you
should consider disclosing the information that you store to your
Q: How can you access
databases from JSP applications?
A: The JSTL provides tags
used to perform queries or modify tables in databases. They are very
easy to use. However, in keeping with my earlier advice, I would
limit their use to simply displaying data in the simplest
Q: Describe how you
develop applications using Struts and JavaServer Faces.
A: Struts provides a
great framework for building applications. JavaServer Faces
basically “extends” the Struts model to add presentation components.
They can help produce better designed and more flexible software.
The key to success with these tools is to understand the model and
your own requirements. It’s helpful to start by thinking of your
application as message driven and built of resources to which the
messages are directed. From there, you can easily create the
controllers and other supporting objects that form the basis for
Struts. All that is left is to provide the declarative “glue.”
Using the early
implementation of the Struts-Faces integration library, you can use
JavaServer Faces components for the presentation portion of the
application, leveraging the power of both of these superb tools. Of
course, the “Devil is in the details”, but I can’t get into that
here – there’s simply too much to cover. “SAMS Teach Yourself
JavaServer Pages 2.0 in 24 Hours” gives a brief introduction to
Struts and JavaServer Faces, and there are some other really good
books out there too. Moreover, Sun has a few good forums that can be
helpful, particularly for JSF – which is just emerging. Craig
McClanahan, Struts creator and development lead for JSF,
participates in discussions in the Struts and JSF forums.
Q: Provide more details
on creating JSP applications for international audiences.
A: Java has had great
support for internationalization for a long time. Through the Format
Tag Library, JSTL helps developers create applications suitable for
international audiences. The mechanisms are similar to the way that
other platforms are programmed for international audiences – you
create one or more resource bundles that contain the local-specific
translations and use functions that are adapted specifically to use
the bundles for output. Currency, numbers, and dates are formatted
with utility functions. Like the other JSTL tags, the library is
easy to work with. The most difficult part is getting the
Q: How do you secure your
A: My web site is hosted
on a Linux box that uses IPTables to provide front-line protection.
I also use tripwire and network monitoring software. At the
application layer, I generally use the facilities of the container
for role-based authentication, using modules that tie into standard
mechanisms provided by the operating system or other systems. There
are a number of single-login technologies such as SAML that I like
Q: Describe your latest
A: I’ve recently been
involved in creating a replacement system for a business who has an
online store, and uses web based applications for most of their
business processes. The client also has several large databases that
are made up of content that is sold to the consumer by subscription.
I’ve been concerned with the scalability of the application the
customer uses to search through the data and retrieve the data sets
they are interested in. The application will also help the consumer
find data they are interested in or suggest other research avenues.
On other fronts, I’m
involved in a couple of start-ups – one focuses on a few good ideas
that a friend and I have been talking about for a while. The other
is an exciting opportunity to work with wireless broadband and some
unique applications involving mobile devices. I can’t say much more
In addition, I still work
Q: Where do you see
yourself in five years time?
A: Retired and wealthy.
Wouldn’t we all like to be? Retirement for me probably wouldn’t be
much more restful than what I do today – I have too many interests
to be idle. In actuality, I’d like to see some success in the
projects I mentioned earlier and be able to pursue some other
professional and personal interests. I’ve always enjoyed the
creative end of engineering – and I have lots of ideas to pursue.
Q: You are a
well-respected Java expert. What are your top tips in five major
areas of Java development—you choose what you consider the five most
important areas of Java-related development?
A: Sure! Although I’m
certain I’m being given far too much credit. I hope you won’t mind
if I generalize, though. I think that the most valuable top tips
actually apply to development in general.
Area 1— Develop a solid
An understanding of the
language and the idioms is essential. Several good books are
available that accelerate your understanding of the language and its
use. “Practical Java” and “Effective Java” are two good ones to
start with once you’ve learned something about the language. Once
you start using more advanced features of the platform, look for
specialized training in the topic. Hands-on training is best. If
you’re using a book, do the exercises.
Sun does a superb job of
producing helpful material. With each release of a platform, they
include specifications, a reference implementation, and a set of
blueprints that define the best practices. Read the blueprints. Sun
also often provides tutorials that are well constructed.
Finally, find an
experienced co-worker and “look over his/her shoulder.” Ask to be a
part of their code reviews, just so that you can listen and learn.
If you’re on your own, pick a mature open source project, such as
Apache Commons, and read the source code. Join a user’s group.
Area 2 - Develop an
understanding of design
Although the language is
incredibly good at protecting you from your own coding errors, and
can even enforce some level of good design, it can’t do everything
for you. I’ve seen many poorly constructed applications – often
written by developers who have years of experience with the
language. Start with a great book on Object-Oriented design – such
as “Object Oriented Analysis and Design” by Grady Booch. Learn how
to develop your ideas on paper and communicate them to others with
UML. Another great book that helps in both of the areas I’ve
mentioned is “Fundamentals of Object-Oriented Design in UML” by
Area 3 - Develop an
understanding of construction
Improve your ability to
implement high quality software. Now that you have an outstanding
design, make it “hit the pavement” so that it performs. Your
software should behave correctly, run efficiently, and be
maintainable. In the notes for the first area, I already mentioned a
few helpful books. Some of my other favorites within this area are
“The Practice of Programming” By Brian Kernighan and Rob Pike and
“Code Complete” by Steve McConnell. Although these books use other
programming languages to illustrate the concepts, the advice is
priceless. And, if Java is the only tool in your belt, take the time
to become familiar with another language. Java is as close to a
Swiss Army Knife as I have found – I’ve done small and large
applications with nothing else - but there are occasions when you
need an axe or jeweler’s screwdriver. If you learn C++, you’ll be
able to read the VM source!
Area 4— Become familiar
Most developers are
familiar with the “Gang of Four” patterns book, “Design Patterns.”
If you don’t own it, add it to your library. It’s one of the best
investments you’ll make. It will expose you to a few good reusable
solutions to common problems. If you really catch on, you’ll
approach your work differently – and start “painting” with more than
To get started using
patterns in Java, a good “template” book is one like James Cooper’s
“Java Design Patterns.”
Area 5—Learn how to
I have always appreciated
the effort to raise the standards for software and developers. I was
exposed to David Parnas’ work a few years ago and became interested
in the process of creating software and software theory. E.W.
Dijkstra is also interesting reading. Google for some of their
papers. To come up to speed more quickly, and for good advice about
all aspects of software development, read “The Pragmatic Programmer”
by Hunt and Thomas. I also recommend Steve McConnell’s other books.
I have all of them.
Area 6— Leave room for
the thing you haven’t thought of yet, or for the idea somebody else
might think of.
There’s always something.
Here is where I would do some listening, if I could, to the readers.
There is usually something to be gained from an exchange of ideas.
Q: What kind of computer
setup do you have?
A: My primary computer is
modest. It’s home-built with an AMD Athlon 1.2 GHz processor and 768
MB of RAM. I use a wireless (Super) 802.11g network connection that
provides a 45 Mb/s connection to the rest of my machines. I needed a
wireless connection to my office, and I have been pleased with the
results. My other machines are slower Athlon based machines. There
are three of these – two of which are running Linux . Linux performs
very well even on machines like these. These machines host Apache
2.0, MySQL 4, CVS, DNS, email, and the other usual services. I also
run Tomcat, and JBoss. For project management, I use GForge. The
other is a windows box for doing .NET backend development.
Q: Alan, we were indeed
fortunate for the in-depth answers and insights you have given us.
Thank you again for your time, and consideration in doing this
A: Thank you.