Re: java.sql.Timestamp: Bug or...

From:
Patricia Shanahan <pats@acm.org>
Newsgroups:
comp.lang.java.programmer
Date:
Fri, 02 Jul 2010 06:25:58 -0700
Message-ID:
<-p6dnVC7mvZ_dbDRnZ2dnUVZ_hudnZ2d@earthlink.com>
Lew wrote:

Hole wrote:

I've noticed some strange problems in my app...after few hours of
debugging I found out that problems are in java.sql.Timestamp...

Please, if you have spare time, could you look at the following code
and test it with some dates?:

public static Timestamp toSqlTimestamp(String date, String fmt) throws
ParseException, Exception {


Declaring 'throws Exception' is an antipattern.

         Timestamp res = null;
         try {
             SimpleDateFormat f = new SimpleDateFormat(fmt);
             res = new Timestamp(f.parse(date).getTime());
         } catch(ParseException pexc) {
             throw pexc;


This catch clause is redundant since the method already rethrows the
exception without it.

         } catch(Exception exc) {


Catching 'Exception' is usually an antipattern.

Failing to log or handle exceptions is an antipattern.

             throw exc;
         }
         return res;
     }

This code strangely returns wrong hours, but only whit particular
dates. For example, time from 2009-03-29 02:00:00 to 2009-03-29
03:00:00 (this excluded) returns a timestamp of one hour more...

This is the output of a test program I made:

Original: 2009-03-29 01:45:00
toSqlTimestamp: 2009-03-29 01:45:00

Original: 2009-03-29 02:00:00
toSqlTimestamp: 2009-03-29 03:00:00

Original: 2009-03-29 02:15:00
toSqlTimestamp: 2009-03-29 03:15:00

Original: 2009-03-29 02:30:00
toSqlTimestamp: 2009-03-29 03:30:00

Original: 2009-03-29 02:45:00
toSqlTimestamp: 2009-03-29 03:45:00

Original: 2009-03-29 03:00:00
toSqlTimestamp: 2009-03-29 03:00:00


What time zone is the 'DateFormat' under? I'm guessing that its
Standard Time is one hour after GMT, say in Europe somewhere.


Also, does that time zone do daylight saving time, and if so when do
clocks go forward? I suspect that may be involved because the OP says
only some dates are affected, and the examples of affected times are
around 2 a.m. on a Sunday morning, a popular time for adjustments.

Patricia

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