Pervasive computing refers to a generation of technology that will integrate smart things that link with the computing infrastructure. The post-PC era will bring devices that won't bother us until we're asked to be involved in their operation. The Java language, its associated class libraries, and virtual machine technology are the keystones to making the pervasive world possible.
The primary objective of this article is to demonstrate to readers how their design and code can evolve to use a pattern. The goal of this evolution is the Observer pattern.