IntelliJ IDEA, xml namespaces for urn: java?

Question

I want IntelliJ to learn and read the classpath for names in my web.xmlor other xml files.

For instance:

<whatever:HeartbeatService xmlns:heartbeat="urn:java:whatever">
    <ee:Named xmlns:ee="urn:java:ee">HeartbeatService</ee:Named>
    <inject:Singleton xmlns:inject="urn:java:javax.inject"/>
</whatever:HeartbeatService>

IntelliJ displays urn:java:whatever, urn:java:eeand in urn:java:javax.injectred, with the error message: "The URI is not registered (Settings | Project Settings | Schemas and DTD)."

Perhaps there is some way to register the class path that I just miss?

Answer 1

Alt + Entering a red namespace declaration at the top and then "Manually set an external resource."