I have a domain object that uses a component to hold various date related information. The component uses GregorianCalendar to hold actual date information. This all works fine as far as saving and retrieving the domain object and the component. However, after retrieval one of the GregorianCalendar objects in the component (mySimpleDate, the only one that actually has a value in this case) is one hour (exactly) ahead of what its original value was (and what is stored in the database).

Hibernate version:
3.0.2

Mapping documents:
<class name="org.egcrc.cfr.normalized.NormalizedRecord"
table="NORM_REC"
lazy="true">
...
<component name="myEventDate" class="org.egcrc.cfr.common.Date">
<property name="myIsSimpleDateApproximate" column="EVENT_DATE_IS_APPROX" type="boolean"/>
<property name="myMaxDate" column="EVENT_MAX_DATE" type="java.util.GregorianCalendar" />
<property name="myMinDate" column="EVENT_MIN_DATE" type="java.util.GregorianCalendar"/>
<property name="mySimpleDate" column="EVENT_DATE" type="java.util.GregorianCalendar"/>
</component>
...
</class>

Code between sessionFactory.openSession() and session.close():
...
NormalizedRecord normRec1 = bisRecord.normalize();
Transaction tx = session.beginTransaction();
session.save(normRec1);
tx.commit();
...
Transaction tx = session.beginTransaction();
NormalizedRecord normRec2 = (NormalizedRecord)session.get(NormalizedRecord.class, id);
tx.commit();

Full stack trace of any exception that occurs:

Name and version of the database you are using:
DB2

The generated SQL (show_sql=true):

Debug level Hibernate log excerpt:
This message occurs as the session.get() us executed. The date is correct here:

DEBUG org.hibernate.pretty.Printer - org.egcrc.cfr.normalized.NormalizedRecord{myEventDate=component[myIsSimpleDateApproximate,myMaxDate,myMinDate,mySimpleDate]{myMinDate=null, mySimpleDate=1935-11-30 23:00:00, myMaxDate=null, myIsSimpleDateApproximate=false}, mySourceId=, myRoles=<uninitialized>, myRecordType=BIRTH_INDEX_RECORD, myCreateDate=2005-09-27 12:45:10, myId=6}

This sounds like a daylight savings time or timezone issue, but I have checked those on the DB2 server and the workstation I run the application on and there is no difference.

you should always compare the actual milliseconds value to validate the contents of dates - not their printed value.

I was a bit incorrect in my original post. Here are the various representations of my date-time value:

1. The original string: "12/1/1935"

2. I parse this and create an instance of GregoriqanCalendar whcih has these values:
year=1935, month=11, day=1, hour=0, minute=0, second=0

NOTE: The month is 0-based so this is correct.

3. I save the object containing this date into the database. In the database the field value looks like this:

1935-11-30 23:00:00

This is one hour less than it should be. This must be either a DB2 problem or a Hibernate problem.

4. Now i retrieve the object containing the date. As expected it creates a GregorianCalendar with the wrong value:
year=1935, month=10, day=30, hour=23, minute=0, second=0

Hibernate correctly instantiated the GregorianCalendar from the data, so the finger seems to be pointing at DB2.

I'm actually comparing the dates using equals().

assertEquals(normRec1, normRec2);

The equals method traverses through the objects and eventually compares the date components I described in my original post. Exactly what GregorianCalendar.equals() does I don't know but it does not just check for identity. In any case the two dates have values that differ by an hour. The millisecond values are not the same.

Hi,

this is may be a problem of JAVA day light saving.

If you try


it will probably print "true".


let me know if this is the problem...
Pedro

I solved this problem by replacing the DB2 driver.