True, the XMLDB and XQJ interfaces are not included in our Maven
repositories; instead, they are dynamically located by Maven itself.
You'll find the interfaces e.g. at the following locations:

 http://www.inf.uni-konstanz.de/dbis/basex/maven/javax/xml/xquery/xqj-api/1.0/
 http://www.inf.uni-konstanz.de/dbis/basex/maven/org/xmldb/xmldb-api/1.0/