There are several problems here. First, in your DB if you defined your column as date or timestamp you do NOT have any control of how the DB internally stores it. You may have control of how it would be represented by a client that reads it from DB. But that is all you need.
Second, Avoid outdated class Date and use java.time package. In your case, you might be interested in LocalDateTime or maybe ZonedDateTime class.
Once you change to appropriate class change the annotation
@DateTimeFormat(pattern = "yyyy-MM-dd hh:mm:ss")
to
@JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd HH:mm:ss")
For more details see the answer to this question