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The WDN Symbian DevZone Book Review... Wireless Java for Symbian Devices
by Richard Bloor, April 8, 2002
When compared to other operating systems, and more particularly mobile operating
systems like Palm and Windows CE, the Symbian OS is poorly served with print
books. I suspect that this was behind the reason why Symbian, in June 2001, in
collaboration with John Wiley and Sons, launched the Symbian Press. According to
David Wood, Symbian's EVP Technical Consulting, the goal is to "communicate
authoritative, timely, relevant and practical information about the Symbian OS and
related technologies". The first publication from this joint venture is
Wireless Java for Symbian Devices by Jonathan Allin published in November 2001.
Wireless Java for Symbian Devices by Jonathan Allin
While there are books aplenty on Java for the PC and server world and a few titles
dealing with MidP Java for mobile phones there is a real shortage of books on the
flavors of Java for PDAs and Smartphones. So those taking on the challenge of
migrating their Java skills and applications to the mobile world, or more particularly
the Symbian OS, can take heart as Symbian have put together a wide ranging review
of the practicalities and opportunities present by PersonalJava on the Symbian OS.
The first three chapters opening the book are an introduction to the Symbian OS.
They tread a difficult line given that the reader may or may not have any previous
knowledge of Symbian. Unfortunately I felt the opening lacked the detail which
would be useful to a first timer without adding to the knowledge of someone who
might already have some familiarity with Symbian. My advice would be to skip these
chapters if you already have some familiarity with Symbian, if not read them but
also take a look at the white papers on Symbian's web site.
Wireless Java for Symbian Devices
The next section gets down to the real meat providing a primer for PersonalJava and
Javaphone. This is followed by a discussion about games, user interface design and
code optimization. These sections, as is the whole book, are illustrated with
practical code examples, explained clearly and, with the exception of some larger
examples, in some detail. The discussion on PersonalJava and JavaPhone are
excellent introductions for those who are not familiar with these components of the
Java technology toolkit. The examples are also well thought out and illustrate the
key concepts well. The section on games may be disappointing to some focusing as
it does on multi-user strategy games and giving little insight into graphics based
action games. However given the current lack of high speed, low latency networks
and the focus on wireless the brief exploration is probably understandable.
Strangely the chapter on user interfaces is illustrated largely with examples from
Epoc v5, which power the current range of Psion devices. While the principals
discussed are similar for both it seems a strange decision given that I would expect
most readers to be interested in developing for newer smartphones like the Nokia
9210. However this is probably simply indicative of the drawback of print media, it
takes a while to get to print so the latest changes are not always reflected.
The section on optimization provides a wealth of detail. Given the importance of
optimization in creating good applications for smartphones this section is worthwhile
even for experienced Java developers who will be familiar with some of the ground
covered. Issues such as Object creation and reuse, string manipulation, containers
and graphics are given thorough treatment. A semi-fictitious case study of a
queuing application is used to illustrate some of the principals discussed, before
reviewing profiling and heap analysis tools. There is then a discussion of good
design patterns, memory management (including how to simulate low memory when
running the PC emulator), compilers and finally the benefits of Obfuscators in
reducing the size of code.
Wireless Java services are dealt with in the next section of the book. The first
chapter reviews the issues involved in creating a wireless service, and lists a number
of potential applications. Discussion then moves to Symbian OS security. This
chapter includes a good overview of Public Key Infrastructure (PKI) and covers both
native features (including some not available to Java) and PersonalJava security.
Again the discussion is rounded off with a code example. The section is completed
with a discussion of the issues around provisioning these services. All aspects of the
life cycle, discovery, installation, authorization, update and removal are covered
before the chapter closes with a review of the current state of standards.
Two case studies are provided in the penultimate section. These have been,
provided by Symbian Partners Telenor and Digia, and they illustrate possible
wireless services and how they could be implemented using PersonalJava. The first
example provided by Digia is a simple conference application providing a shared
electronic white board and chat facility implemented on both Quartz and Crystal
(Nokia 9210) interfaces.
The second example is a travel assistant developed by Telenor, which combines
information from several sources. It provides an illustration of the methods that
could be used to mobilize existing web based services for a smartphone application
using a gateway server.
Finally the book wraps up with a look at JNI and the forward road map for
Symbian's Java implementation.
Overall Wireless Java for Symbian Devices provides a view into most aspects of
PersonalJava development for the Symbian OS. It is well supported by good clear
examples and has drawn on the experience of Symbian partners to provide insight
into the issues and opportunities in creating PersonalJava applications and services.
If you are a Java developer with interest in developing for the Symbian OS or have a
real world project coming up, then you should find space on your Java bookshelf for
this book.
You can find more information on the book at Symbian's web site here, which
includes additional downloads of software examples. There is also an interview with
the author, Jonathan Allin.
for the book support
for the interview
Other Books about Symbian
"Professional Symbian Programming" from Wrox press was published in 2000.
While it deals with v5 of the OS, still remains very useful for C++ developers as it
contains a wealth of information on the core of the operating system.
Symbian Press is due to publish a new title "Symbian OS Comms Programming" in
June 2002. There are also rumors that a book on developing for the Nokia Series 60
interface will also be out shortly.
About the "WDN Symbian Guy" Richard Bloor:
Richard Bloor has 16 years experience in the IT industry. His earlier
work was largely in design and development of commercial and
manufacturing systems but more recently has focused on
development and test management of government systems.
Richard Bloor is the Mobile Applications champion at System
Architecture consultancy Equinox of Wellington, New Zealand.
Richard can be reached at rbloor@wirelessdevnet.com.
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