Java, Hibernate, MySQL - store UTC date-time

问题:

I saw here on SO a few related questions (like this one and of course, this one)... Essentially, what I want is to store date-time as UTC, and let application user choose the time zone he wants to display date-time in.
Since it seems that date-time fields are affected by the underlying JDBC driver, I wonder if this is an acceptable way to go about storing UTC date-time:

• Set both MySQL and Application server machine to UTC time zone (no need to separate)
• Both MySQL and JVM should pick up underlying system time settings (if not instructed otherwise)
• Use DATETIME table columns on MySQL side
• Use java.util.Date as corresponding mapping on Hibernate side (I guess java.sql.Timestamp could be used too)
• Let the application worry about interpreting date-time fields - i.e. let the user choose preferred time zone

Is this OK?

EDIT
To clarify - here I meant to refer to timestamps created strictly on the server (e.g.date-time of record creation). So the application server instantiates Date objects (new Date() equals current date-time on the server, and this is really time zone agnostic).
Now if a client user wants to supply some date for searching/filtering purposes, here is where the transformation from client-local time to UTC should take place, IMHO...

回答1:

I would suggest another simple approach which would independent of machine timezone settings.

• Instead of setting the timezone of the server machine, set the timezone of JVM. This can be done via system properties. On Windows example would as follows

set JAVA_OPTS=%JAVA_OPTS% -Duser.timezone=GMT

• For MySQL here is the reference for doing it.
• Now this this make sure that all your date-time are in GMT
• Keep the timezone as configurable property OR it can be user dependent as well. So you store timezone for each user if the users belong to different geographies.
• Whenever, a date is needed, after you select it from the database, apply the timezone to get the correct time.
• The advantage of this approach is that this will work for the all the timezone users. Meaning the user will see the correct time as per their timezone.

回答2:

Use locales to implement internationalization.