I'll kick off the series by reviewing a few of the basics to show you what you're up against and where JAXP/XML/XSLT will come in handy.
Developing for wireless applications brings its own set of challenges, including a number of display and browser issues. In this three-part series, I'll explain how to use the Java APIs for XML Processing (JAXP), along with XML Stylesheet Language Transformation (XSLT), to solve some of those problems and build content that the wireless device can understand.
Screen resolution
Back in the old days (does anyone remember 1994?), the cutting-edge technology was client-server GUI development with languages such as Visual Basic and PowerBuilder. One of the problems with early GUI development was that you never knew which monitor resolution to program for. If the application was viewed on a monitor using 800 x 600 resolution, it would not fit on desktops using a lower resolution. If the monitor resolution was high, your applications would be too small to see.
Internet development partially solved this problem. By using markup tags to define the GUI, the application could use more of a relative, as opposed to absolute, positioning. This meant that the GUI would resize somewhat when the user resized the browser. By default, Java applets also use this system of relative positioning.
So what's the point? Screen resolution problems are an even larger issue on handheld devices. High-end PDAs such as the Handspring Prism have a resolution of 160 x 160 pixelsââ,¬"a far cry from traditional monitors that have a resolution of five times that much. Mobile phones, on the other hand, are on lower end of screen resolution. A Nokia 6185i has only five lines of resolution. So what do you do? Write completely different applications for each device? That's not really feasible. But, by the end of this article, you'll see how you can use JAXP/XML/XSLT to regulate what content gets served to which devices.
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