The message is correct, although the idea might seem surprising. Properties files and bundles are intended to be placed in the same directories as your
java classes, which means that they can be found on the app's classpath. Treat them exactly like you would treat your classes, which means refer to them using fully qualified "classnames".
For examples, let's say I have an "appResources.properties" file and I want to put it in "WEB-INF/classes/com/mousetech/myapp/resources", since WEB-INF/classes is a fundamental part of any WAR's classpath. The fully qualified resource name would then be "com.mousetech.myapp.resources.appResources.properties".