Jackson Serialization sometimes borking with timezone

Question

(I am in the UTC+2 timezone, which I assume is the 2 hour difference).

I'm busy writing a JSON RESTful API that's part of a Grails application (2.0.3 on this project in particular, but this problem occurs in other versions). I use Jackson for Serialization and Deserialization of Json, and the JsonService's configuration looks like this: http://pastebin.com/JacytMuF

So multiple Domain objects have values collated and represented in a single DTO (in this case it's a simple map), and these are just passed to the JsonService to convert to Json, which is returned (to a request). All of the fields are serialized correctly, with the exception of two of the (several) Dates, which are off by 2 hours. I can for example run:

  db_dev=# select next_billing_date from account where code = 'CATS001';
  next_billing_date  
---------------------
 2013-06-20 00:00:00

and this is verified to be correct (within memory) by this little action

def checkTimezone() {
        Account acc = Account.findByCode("CATS001")
        log.error(acc.nextBillingDate)
    }

which returns

ERROR mash.TestController  - 2013-06-20 00:00:00.0

as expected. Furthermore, I can check that nothing tampers with the in-memory value by doing, within the RestAccountController:

def show() {
         ...
         def ans = [ code: ac.code, nextBillingDate: ac.nextBillingDate ] 
         log.error("CATTTTSSSSSSSSSSSSSS::::: ${ac.nextBillingDate}")
         [ans: ans]
    }

(returning)

ERROR mash.RestAccountController  - CATTTTSSSSSSSSSSSSSS::::: 2013-06-20 00:00:00.0

Yet when I hit the relevant endpoint, I get:

nextBillingDate": "2013-06-19T22:00:00.000+0000"

Which is off by 2 hours. The nextBillingDate property is a normal Java Date object, the underlying database is psql:

next_billing_date           | timestamp without time zone | not null  | plain    |

And hence I am a bit lost for ideas on why it's randomly deducting 2 hours. I can see why 2 hours is the magic number (timezone differences), but I cannot explain why it's offsetting the Date on some objects (or indeed only on some subset of the Date objects).

Have a look at this, if it is source of any inspiration: [http://stackoverflow.com/questions/15734768/jqgrid-date-formatter-not-applying-local-time-offset-correctly-grails](http://stackoverflow.com/questions/15734768/jqgrid-date-formatter-not-applying-local-time-offset-correctly-grails) — lucke84, May 21 '13 at 16:34
I suggest you to use the same `SimpleDateFormat` that you declared in your `JsonService` to print your debugs. — , May 21 '13 at 18:29

score 1 · Accepted Answer · edited May 23 '17 at 11:57

Few things to check:

Is your JVM set to UTC timezone by default?
Is the timezone in database row UTC? In your case I don't think db cares about timezone.

Option:

If JVM is set to UTC by default then, you would see the offset of 2 hours. In order get the timestap in your zone which is UTC+2:00 you can set the default timezone to your zone by like below in Bootstrap.groovy

TimeZone.setDefault(TimeZone.getTimeZone("GMT+2:00"))

Note:- Refer GMT vs UTC to find the difference.

Jackson Serialization sometimes borking with timezone

1 Answers1