Convert LocalDate to LocalDateTime or java.sql.Timestamp

Embracing Time zones when converting

When the time zone matters, we bring in the ZonedDateTime:

ZonedDateTime zonedDateTime = date.atStartOfDay(ZoneId.systemDefault()); // "Same time, different zone!"
Timestamp timestamp = Timestamp.valueOf(zonedDateTime.toLocalDateTime()); // "And... back to our regular timestamp"
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By using ZonedDateTime, you're ensuring the time zone isn't lost in translation.

JPA and JDBC 4.2+ compatibility

If you're a JPA user, implement the AttributeConverter to tackle Java 8's time types:

@Converter(autoApply = true) // "Be prepared. That's the JPA convertor's motto!"
public class LocalDateConverter implements AttributeConverter<LocalDate, Date> {
    // Insert conversion methods here
}
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With JDBC 4.2+ drivers, it's a smooth sail as they can talk java.time directly with your database.

A Fraction of seconds does matter

If you're not mindful, converting between LocalDate, LocalDateTime, and Timestamp could chop off fractional seconds:

LocalDateTime preciseTime = LocalDateTime.now(); // "Maybe being precise isn't that hard!"
Timestamp preciseTimestamp = Timestamp.valueOf(preciseTime); // "Ah yes, the art of nanosecond precision"
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Truncation is a real problem, but with this, we avoid losing those precious nanoseconds.

Capturing current moment using Instant

To capture the current moment in UTC, java.time.Instant is at your service:

Instant instant = Instant.now(); // "What's the time Mr. Wolf? Right now!"
Timestamp currentTimestamp = Timestamp.from(instant); // "Present moment in a neat timestamp package!"
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The Instant class lends a hand to precision and makes moment capturing seem like child's play.

Proper DateTime formatting

Get yourself a custom string representation of date-time with a DateTimeFormatter that dances to your tune:

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"); // "Hey Formatter! Strike a pose!"
String formattedDateTime = timestamp.toLocalDateTime().format(formatter); // "Strike the pose, Formatter!"
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Java 8 time types and database compatibility

It's essential to remember your database and its version when dealing with Java 8's time types:

• Postgres (version 9.4.1208+) and
• HSQLDB (version 2.4.0+)

both natively support Java 8 Time API.

Quick and efficient Timestamp creation

You're one line away from a Timestamp with the current date & time:

Timestamp currentTimestamp = new Timestamp(System.currentTimeMillis()); // "In this house, Timestamp rules!"
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Key takeaways while converting

• Consider the time zone because not everywhere is 'right here'.
• With JPA and JDBC (4.2+), you're playing with the big boys now.
• Fractional seconds do count! Don't let them disappear.
• Go from zero to hero real quick with java.time.Instant.
• Remember to wear the right DateTimeFormatter.