[prev in list] [next in list] [prev in thread] [next in thread] 

List:       mysql-java
Subject:    Re: help with preparedStatement.setTimestamp with Calendar
From:       Shankar Unni <shankarunni () netscape ! net>
Date:       2006-04-17 20:00:36
Message-ID: e20s55$p6g$1 () sea ! gmane ! org
[Download RAW message or body]

Dan Jatnieks wrote:

> e.g. I have 2006-01-01 00:00:00 (UTC) as the timestamp value and expect that
> when it is written to the database it will become 2005-12-31 19:00:00 (EST).

So far, so good.

> Calendar utc = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
> Calendar cal = Calendar.getInstance("EST");
> PreparedStatement stmt = m_conn.prepareStatement(sql);
> 
> ...
> 
> // Use the UTC Calendar to create a new timestamp and the target
> // Calendar to adjust it to the correct timezone and set the
> // timestamp value.
> Timestamp tstamp = new Timestamp(utc.getTimeInMillis());
> stmt.setTimestamp(2, tstamp, cal);

But this isn't doing anything (at least, I don't see how you plan on 
getting the time "00:00:00" from this. How do you set the time in the 
calendar called "utc"? By default, a newly-created calendar contains the 
current date and time.

Did you do

   utc.set(Calendar.HOUR_OF_DAY, 0);
   ...

etc., to set the time in "utc", before you called utc.getTimeInMillis()?

By the way, a word of warning: if your program is multi-threaded, don't 
try to share a Calendar instance globally like this (for "cal", or for 
"utc", for that matter). Calendar is not thread-safe. Always allocate a 
local Calendar instance on stack and use/modify it on the spot.


-- 
MySQL Java Mailing List
For list archives: http://lists.mysql.com/java
To unsubscribe:    http://lists.mysql.com/java?unsub=mysql-java@progressive-comp.com

[prev in list] [next in list] [prev in thread] [next in thread]