I think there's an error in this XSD which prevents me from using the "javaee" elements you intend to import.

First, the "javaee" namespace is declared as http://xmlns.jcp.org/xml/ns/javaee in the XML header, but then (surprisingly) the <xsd:import> uses another namepace:

<xsd:import namespace="http://java.sun.com/xml/ns/javaee" schemaLocation="web-app_3_1.xsd"/>

I'm fairly confident this is wrong. It's importing under the old Java EE namespace – not the new one which the header correctly declares. Hence, consumers are unable to get the "javaee" elements.