Date conversation with time zone information - spring-boot

Question

I have one issue. Solutions might be there already in this forum but I couldn't find anything. Please share if it's already answered.
The scenario is as below.
Request is coming in CET to my application which is running in UTac time zone. My backend stored procedure is running in CET zone. The time that is passed in as string with cet offset I need to send same as SQL date with same date to my backend.
Current implementation is:
Convert string date to offsetdate. Then create Instant from that offsetdate and then util date using that instant. Once I have until date I am converting that to SQL Date.
So here issue is if input request us 2012-07-15T00:00:00+02:00 then when applications which is running in UTC is giving correct offset date with cet offset information but when it is converting to instant then always UTC will come. So new date is 2012-07-14T00:00:00Z and because if this my util and SQL date is also coming 1 day behind.
Can anyone please guide if there is any other way where I can create SQL or util. Date for same date irrespective of any time zone?
Because the expectation is request can come with any time zone and we need to understand that zone and then convert or use accordingly and same date should go to back end.
API developed with: Spring boot with JAVA 8 and backend we are accessing using stored procedure where stored procedure is expecting in SQL date.

Answer 1

Since you can use OffsetDate and other classes from java.time, the modern Java date and time API, you should no longer be using java.util.Date nor java.sql.Date. Those classes are poorly designed and long outdated, and the modern API offers all the functionality you need. You might have thought that you needed a java.sql.Date for storing into your SQL database. But with JDBC 4.2 (or a newer JPA implementation such as Hibernate) you can directly store a LocalDate there, which you will prefer.
String requestString = "2012-07-15T00:00:00+02:00";
OffsetDateTime dateTime = OffsetDateTime.parse(requestString);
LocalDate date = dateTime.toLocalDate();
System.out.println("Date is " + date);
This prints:
Date is 2012-07-15
No day has gone lost. To save do for example:
PreparedStatement ps = yourDatabaseConnection.prepareStatement(
"insert into your_table (your_date) values (?);");
ps.setObject(1, date);
ps.executeUpdate();
Sometimes we need to pass an old-fashioned type to a legacy API that we cannot afford to change right away. If this was your reason for wanting a java.sql.Date, convert like this:
java.sql.Date sqlDate = java.sql.Date.valueOf(date);
System.out.println("Old-fashioned java.sql.Date is " + sqlDate);
Old-fashioned java.sql.Date is 2012-07-15
Still no day is lost.
Edit: If what your legacy API requires is a java.util.Date, you will need to know the way to convert:
Instant startOfDay = date.atStartOfDay(ZoneId.systemDefault()).toInstant();
Date oldFashionedUtilDate = Date.from(startOfDay);
System.out.println("As old-fashioned java.util.Date: " + oldFashionedUtilDate);
When I run with a default time zone UTC the output is:
As old-fashioned java.util.Date: Sun Jul 15 00:00:00 UTC 2012