scalaxb-mvn-plugin supports all parameters available to sbt-scalaxb.
/**
* Map of namespace URIs to package names for generated classes.
* <br/>
* This option can be used to override the <code>packageName</code>
* parameter (see above) for elements in specific namespaces. The mapping
* between namespace URIs and package names can be specifying any number of
* <code>packageName</code> elements within the <code>packageNames</code>
* element. For example:
* <pre>
* <packageNames>
* <packageName>
* <uri>
http://example.com/service1</uri>
* <package>com.example.service1<package>
* </packageName>
* <packageName>
* <uri>
http://example.com/service2</uri>
* <package>com.example.service2<package>
* </packageName>
* </packageNames>
* </pre>
* @parameter
*/
private PackageName[] packageNames;
-eugene