I had been hoping that these methods would get around my ahving to use 
the Clob directly, and to keep me away from using Oracle-specific code.

Method 1 didn't get me past the 4k character limit.  Something 
like 'too much data for this datatype (4000)' (I didn't record the 
error).

Method 2 needed extra implementation to work with the current version 
of Hibernate (fromStringValue(), toString(), getReturnedClass()), 
which I implemented in the way that seemed best -- there's not a lot 
of documentation on the nature of these methods.  That got me as far 
as getting 'No more data to read from socket.'  Disabling JDBC batches 
got me to 'No more data to read from socket.'  All the references to 
that error point me to the more complicated Oracle/Clob handling 
routines, so I'm going to have to go that way for the time being, and 
then circle back into figuring out what's necessary to support a 
direct string.

If anyone has additional pointers, I'd be happy to hear 'em.