The closest equivalent I have done is getting an object of type
org.postgresql.jdbc4.Jdbc4Array
For that, I was able to extract using
data{1}.getArray
I think the general idea is that you have a class that you need to apply the appropriate Java method to. For me, that was "getArray", but for you it is presumably different.
This page looks like it has methods that you may be able to implement: http://jdbc.postgresql.org/development/privateapi/org/postgresql/util/PGInterval.html
Maybe that will aim you in the right direction.
