I have a java.sql.Date object and want to transform it to a java.time.LocalDateTime object.
For comparison, I am able to do a similar transformation using java.util.Date:
java.util.Date utilDate = new java.util.Date(sqlDate.getTime());
System.out.println("date with time: " + utilDate);
This answer doesn’t work for me, as my java.sql.Date does not have a getTimestamp method.
For reference, this question addresses the opposite transformation.
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Answer
You are using terrible date-time classes that were years ago supplanted by the modern java.time classes defined in JSR 310.
- Do not use
java.sql.Date - Do not use
java.util.Date - Do not use
java.sql.Timestamp - Do not use
java.util.Calendar
Use only java.time classes.
For exchanging date-time values with a database, use JDBC 4.2 or later.
The java.sql.Date class pretends to represent a date-only value.
If you are handed a java.sql.Date object, immediately convert it to a java.time.LocalDate. Use the new method toLocalDate added to that old class.
LocalDate localDate = myJavaSqlDate.toLocalDate() ;
You asked for a java.time.LocalDateTime object. You have the necessary date portion. Now you need to assign the time-of-day portion.
LocalTime localTime = LocalTime.of( 15 , 30 );
Combine.
LocalDateTime localDateTime = LocalDateTime.of( localDate, localTime ) ;
A LocalDateTime is inherently ambiguous. 3:30 PM 🕞 in Japan 🇯🇵 is a different moment than 3:30 PM 🕞 in Morocco 🇲🇦.
To determine a moment, a specific point on the timeline, place your LocalDateTime within the context of a time zone. You get a ZonedDateTimeObject.
ZoneId zoneId = ZoneId.of( "Asia/Tokyo" ) ; ZonedDateTime zonedDateTime = localDateTime.atZone( zoneId ) ;
To view that moment as seen in UTC, with an offset from UTC of zero hours-minutes-seconds, extract an Instant.
Instant instant = zonedDateTime.toInstant() ;