Try using "java:java.lang.Boolean" or "http://www.w3.org/2001/XMLSchema#boolean
elmo-codegen-1.0-beta2 does not support primitives. However, the snapshot version uses them if the cardinality of the property is one.
Replacing java:#boolean with http://www.w3.org/2001/XMLSchema#boolean
worked perfectly. Now have a problem with
org.openrdf.elmo.exceptions.ElmoConversionException: Unknown datatype: java:java.lang#Class
Many Java classes can be used as literals by using "java:" + full class name for the datatype. So in this case you could use "java:java.lang.Class".
Thanks for the quick and helpful response: it now works. This would be a bug in the codegen for owl generation, where boolean should generate as http://www.w3.org/2001/XMLSchema#boolean
and all java datatypes to use "java:" + full class name.