The directory in each JAR that is exposed is 'META-INF/resources'. Any files in this directory are accessible just like resources in the root of the WAR. Which leads to...
JSPs in JARs
JSP files in META-INF/resources also get the special treatment. This allows you to package your application as a set of JARs. This is useful if there are multiple customers and a set of features are customized for each one. The JSPs and action classes that provide the default behavior can be packaged as a shared JAR. The customizations can override the defaults. The servlet spec states that resources in the WAR will override any resources in a JAR when they have the same context relative path.
The application can be accessed at http://localhost:8080/web-app/Index.action.