blob without largeobject api

I need to insert a Blob into a table without using
org.postgresql.largeobject.*; classes, that's because the db pool I'm
using (Resin) doesn't allow me to cast:
((org.postgresql.PGConnection)db) to get access at the Postgres
LargeObjectAPI.

// Generates ClassCastExep.
LargeObjectManager lom =
((org.postgresql.PGConnection)db).getLargeObjectAPI();

Since I'd like to keep using the same type of connection (without
changing the pool manager or directly connecting to the db) is there a
way to insert Blob (oid) data into a table without using the large
object api?

Looked in the examples under src/interfaces/jdbc/ but all blob examples
uses that type of access.

Thank You

--
Edoardo Ceccarelli