For a plugin component that wishes to persist settings, it appears that ComponentManager.getProperty() is the way to get them, and they can be set in the web admin “System Properties” pane. Unfortunately, the matching setProperty() does not work. This appears to be because the body of org.jivesoftware.wildfire.component.InternalComponentManager.setProperty() is empty. It should be
The workaround appears to be to use JiveGlobals.setProperty() instead, despite the advice that should be for core components only.