Sebastopol, CA--Although it may seem as if Java programmers are trying to take over the world, the truth is that Java's versatility leads it naturally into new frontiers of technology where, rather than encroaching on the turf of existing technologies, Java has a way of complementing them. Now that Java has come to the wireless arena with the advent of the Java 2 Platform, Micro Edition (J2ME) from Sun Microsystems, the possibilities for new wireless applications and over-the-air distribution models for handheld devices are beckoning to Java programmers. Learning Wireless Java by Qusay H. Mahmoud (O'Reilly, US $34.95) was written to bring these programmers up to speed with wireless Java as quickly as possible.
"Wireless Java can be used to develop any kind of application you can think of," says Mahmoud, "including financial, such as mobile commerce, games, healthcare applications, and others." Organizations will see the benefit of wireless applications when their employees can access critical business information efficiently from anywhere they go. Mahmoud, who has written dozens of articles and tutorials on developing wireless applications, contends that the next big shakeup in the technology industry is wireless, and wireless Java will play an important role in it.
According to Mahmoud, there are numerous advantages to using Java for wireless devices, including the dynamic download of applications that will run even when the device (say, a cell phone) is disconnected from the wireless network or out of the coverage area. A second advantage is that wireless Java provides support for disconnected operations. And, true to Java in general, wireless Java applications are platform-independent: they run on all wireless Java-enabled devices in the same manner.
"The wireless applications we see now are mainly written using the Wireless Application Protocol (WAP). One major difference between WAP and Wireless Java is the interaction model," Mahmoud explains. "The Wireless Markup Language (WML) provides the tags and the possible presentation attributes, but it doesn't define an interaction model. For example, WML defines a SELECT element for providing a list. Some WAP-enabled devices interpret the SLECT tag as a popup menu list while others interpret it as a menu that can be used for navigation. Therefore, there is no standard interaction model defined for this element. If a developer uses it, the application may run well on some devices and poorly on others. Wireless Java applications, on the other hand, provide a clearly defined standard for interaction, using commands that are mapped to soft buttons."
In Learning Wireless Java, Mahmoud introduces the Connected Limited Device configuration (CLDC) and the Mobile Information Device Profile (MIDP) for developing wireless applications, as well as tips and tricks for using Sun Microsystems' lightweight K Virtual machine (KVM). He leads developers through the basics of MIDlet programming, and explains how to use the General Connection Framework for networking support, the high-level and low-level graphical APIs, and the J2ME record management system for persistent storage.
Learning Wireless Java is designed to serve as a quick guide and reference for programmers who are familiar with the Java 2 Standard Edition (J2SE) and are interested in developing wireless software applications. It assumes that the reader is familiar with Java programming and has worked with the J2SE classes. Discussion centers on building safe, compact applications with the graphical interface, database, and networking capabilities that the J2ME supports. In addition, this book also shows how to download applications to the latest J2ME-enabled devices, including the Motorola i50x and i85s phones and upgraded Palm handhelds.
Learning Wireless Java is also available on Safari Books Online
An article by the author, "Invoking JavaServer Pages from MIDlets"
Chapter 5, "MIDP GUI Programming" is available free online
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