Slashdot Mirror


Learning Wireless Java

prostoalex writes: "Teaching developers to program for wireless platforms is probably not an easy task, since there are just so many focus groups in your audience. This book assumes that reader is already familiar with J2EE concepts, has programmed Java and knows the basic APIs for string manipulation and mathematical operations. Learning Wireless Java was a part of my first-month Safari subscription, and since learning to program for Java-enabled phones was a specific task I set for myself, there were some other books on the list that taught you the details of J2ME." Learning Wireless Java (1st Ed.) author Qusay Mahmoud pages 262 publisher O'Reilly rating 9 reviewer Alex Moskalyuk ISBN 0596002432 summary Java developers� guide to programming wireless devices

Qusay Mahmoud's text starts off with an introduction to the Java wireless platform, which includes learning about a good deal of four-letter abbreviations, among which are J2ME, CLDC, and MIDP. In fact, the first three chapters of the book offer a detailed explanation of what those platforms are, what they provide, and how they differ. For those who have done some J2ME programming before, this might seem a bit too detailed, but for beginners venturing into the wireless world these chapters offer helpful information on where to start, what software to download on your machine and what different software packages represent.

In fact, the author goes into detailed explanations of each software package that you need to download in order to start developing for J2ME, and most of the examples, such as setting the path and required system variables, provide step-by-step information for both Windows and Linux platforms.

You don't get to write your own MIDlet until chapter 4, and by that time you should be pretty comfortable with the terminology and abbreviations used throughout the book. Most of the examples in the early chapters of the book involve working with the command-line compiler, and only in section 4.2.6 does the author introduce the J2ME Wireless Toolkit IDE.

The rest of the chapters are concentrate heavily on the classes provided with the J2ME platform. Chapter 5 gives an overview of MIDP GUI programming with abundant examples and source code. Chapter 6 goes into MIDP event handling, where you learn about the ways users interact with their cellular phones and how all those button pushes are interpreted by the K Virtual Machine. Chapter 7 deals with networking issues (you actually get to write your own J2ME application for accessing the server), and Chapter 8 provides an introduction to database programming and storing non-volatile data on J2ME phones. While the application examples are definitely helpful, well-written and commented, I wish the author would spend more time discussing the hardware implementation of server-client communications, since it's not precisely clear how you can test your J2ME Internet-enabled applications on a real phone without calling your cellular operator and using up valuable minutes.

There is also a chapter on Palm OS programming, which was of limited value to me, and thus cannot be properly evaluated in this review. The appendices are very nice, and include the information that most of the developers would probably find very relevant. Appendices A, B, C, D, E, F and G include descriptions of such J2ME API libraries as java.io, java.lang, and java.util (even though the names are the same as J2EE versions, don't be tricked -- to save space, a lot of classes didn't make it to J2ME) as well as complete javax.microedition reference.

The book is a worthwhile read, easy to understand and follow if you have a good knowledge of Java behind you, and can definitely give you a good introduction to wireless development.

You can purchase Learning Wireless Java from bn.com. Slashdot welcomes readers' book reviews -- to submit yours, read the book review guidelines, then visit the submission page.

4 of 110 comments (clear)

  1. this book's title is misleading by cpfeifer · · Score: 5, Informative

    The title of this book should be 'J2ME programming for devices' since there's nothing inherently 'wireless' about the material the author presents. There's no mention of programming for different wireless networks (GPRS, mobitex, flex...) or how to integrate w/existing popular wireless services (SMS).

    --
    it's not going to stop until you wise up, no it's not going to stop. so just give up.
  2. Re:A glimmer of reality... by FortKnox · · Score: 4, Informative

    Java, on anything other than sparc hardware, is utterly slow and bulky.

    How true this was in 1998. But after Java1.2 came out (we're on java 1.4 atm), its been compairable to C++.

    I can't stand it when people talk about how slow java is. When was the last time you coded any java?

    --
    Good quote, too many chars. Seriously, the slashdot 120 char limit sucks!
  3. Re:New kind of slow by Anonymous Coward · · Score: 1, Informative

    If you think Java is too slow, you might still be in the mid 90s. Consider purchasing a time machine instead of a wireless PDA, and I think you'll find 2002 to be a more pleasant time than the 1996 that you've been marooned in.

  4. Re:New kind of slow by klausjensen2 · · Score: 3, Informative


    Wireless + Java = Fast

    When using dedicated hardware Java is much faster on a wireless device that using a Virtual Machine on a Pentium machine, do your homework:

    http://www.arm.com/aboutarm/4X8JCD/$File/ARM926E J- S.pdf