Although I've tried several ways to do this, I thought I'd ask the question first rather than try and fix my attempts...

I am using Oracle db and reveng my hbm.xml and java files. I want to save timestamp information in a column of oracle type TIMESTAMP(6) (see JMS_TMSTP). I have tried to do this, but it keeps converting it to the local timezone. I have a CRTE_DTTM column that is automatically set by the DEFAULT value when the row is created. When i query the database I get:

TIMESTAMP(6) TIMESTAMP(6) DEFAULT SYS_EXTRACT_UTC(SYSTIMESTAMP)
JMS_TMSTP CRTE_DTTM
------------------------- -------------------------
18-NOV-10 09.47.40.033000000 AM 18-NOV-10 04.48.36.707979000 PM

I can see that 'somewhere' it has converted the JMS_TMSTP value from what I set in to in my java app into the local time (Arizona) (currently GMT-7).

So, what's the 'right' way to go about persisting times as UTC in the database using hibernate?

I don't know if this is a good fix, but it seemed to work for me...

I simply put the following code in:
TimeZone.setDefault(TimeZone.getTimeZone("GMT"));

This sets the app's default timezone to what I want to work with. I got the idea from http://blog.jadira.co.uk/blog/2010/5/1/javasqldate-types-and-the-offsetting-problem.html about 1/2 way down, it says:

Note that the same result could have been achieved by simply changing the default time zone, and not passing the Calendar explicitly since the JDBC driver will use the default time zone by default.
...from 10.5 Date, Time, and Timestamp, p47, JDBC 2.1 API Version 1.1, Seth White and Mark Hapner. October 5, 1999 4:39 pm

So it looks like the driver was converting it, and setting the default zone fixes the issue. Anyway, now the db looks like this:


JMS_TMSTP TIMESTAMP(6)
-------------------------
18-NOV-10 09.32.26.026000000 PM

CRTE_DTTM TIMESTAMP(6) DEFAULT SYS_EXTRACT_UTC(SYSTIMESTAMP)
-------------------------
18-NOV-10 09.32.32.801257000 PM