datetime - How to get a java.time object from a java.sql.Timestamp without a JDBC 4.2 driver?

Question

When retrieving a java.sql.Timestamp from a database via JDBC 4.1 or earlier, how does one obtain/convert to a java.time object?

Neither of the open-source JDBC drivers for Postgres is JDBC 4.2 compliant yet, so I'm looking for a way to use use java.time with JDBC 4.1.

Answer 1

New Methods On Old Classes

By using the driver with Java 8 and later, you should automatically pick up some methods on your java.sql.Timestamp object for free. Both java.sql.Time and java.sql.Date have similar conversion methods.

Namely, to convert from java.sql to java.time you are looking for:

• Timestamp::toInstant()
• Timestamp::toLocalDateTime()
• Date::toLocalDate()
• Time::toLocalTime()

To go the other direction, from java.time to java.sql, use the new static methods:

• Timestamp.from(instant)
• Timestamp.valueOf(localDateTime)
• Date.valueOf(localDate)
• Time.valueOf(localTime)

Example:

preparedStatement.setTimestamp( 2, Timestamp.from(instant) );