Some code examples demonstrating what I call a Unified Abstract Configuration Pattern

While preparing for an upcoming session at OSCON 2004, I have collected some sample code for dealing with configuration in java applications. The specified URL lists some demonstrative examples of the idea. The examples deal with XML configuration files, Property file configuration files, Reading mandatory keys, Providing default values, Reading objects from configuration files, Configuration as a data source for objects, XML Child attribute equivalence, and Multiple configuration files treated as a single configuration source. See the code examples.