Demo code for OJUG talk: "Building Cautious Software"

http://www.slideshare.net/KyleDyer/building-cautious-software

Here we have a web application with just one servlet. It calls a service class. This service has a dependency. Everything is wired with Spring. The service can call an old or new version of the dependency based on the value in a property config file loaded from a url via http. There is a special link in the web app that will refresh the app to reload the config file. When multiple instances of the web app are running every node reloads the config even though the user clicks the reload link on only one node.

Kyle Dyer Oct 19, 2010