Before writing a Java Date to an SQL TIMESTAMP column, does JDBC translate the date from the JVM time zone to the database session time zone?

Question

Before writing a Java Date to an SQL TIMESTAMP column, does JDBC translate the date from the Java virtual machine time zone to that of the database session?

For exam

Answer 1

The spec is goofy. The java.util.Date stores milliseconds from epoch in the GMT reference frame. Java.sql.Timestamp is a Date plus nanoseconds in the same reference frame. All the non-deprecated getters and setters use the GMT reference frame. For any sort of sanity, the default time zone for a storing a Timestamp should be GMT.

In a multi-tiered application, the front-end, the driver, and the database server could all be in different time zones. Some of the tiers could be in different time zones at the same time; for instance, if you are doing internet load-balancing across a continent, or if you have a mobile app connecting to a central server. A cloud operating environment would be much the same scenario where you have no idea where the JDBC driver will be running, nor any guarantee that will never change.

The only way I know to achieve consistency in these environments is to only use the parameter setter and ResultSet getter that accept a Calendar, and make sure every app that accesses the data uses the some calender, preferrably GMT or UTC.