Serious Java Programming For The Wireless World

by Shiuh-Lin Lee

In this article, I assume that readers are already familiar with the Java KVM (K Virtual Machine), and I won’t spend time discussing the benefits of KVM applications in the wireless world. If readers are interested on those missing topics, there are several good articles that can be found in the reference section. In this article, I will mainly address the experience gained from a port of my full-featured GIS (Geographic Information System) program from the Java SE (Standard Edition) to the Java ME (Micro Edition) KVM environment.

In 1997, I implemented an Internet Java GIS applet program, JShape, which allows users to load GIS, CAD or image data from the web server and display them on the user’s web browser screen. After Sun introduced KVM, in the latter portion of 1999, I ported JShape to the Java Micro Edition CLDC (Connected Limited Device Configuration) Palm KVM environment as KShape. Also, in the early months of 2000, I implemented a new MShape GIS program, which can run on a Java Micro Edition MIDP (Mobile Information Device Profile) Motorola iDEN phone environment. Due to the different computing environment, the resulted programs have several different features. The following table explains the major differences between Java SE and Java ME (CLDC and MIDP).

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