How to stop LocalDate from changing when being saved to a mySQL database

Question

When saving a LocalDate field (e.g. '2017-09-27') to a mySQL Date column using JPA CriteriaBuilder API, the result is different (e.g. '2017-09-26').

I have validated that my database's timezone is set to UTC using SELECT TIMEDIFF(NOW(), UTC_TIMESTAMP) as the result is '00:00:00'.

I am testing this locally, and I have a timezone of GMT + 2, so my suspicion is that when the conversion occurs from LocalDate to Date, 2 hours are being deducted and producing a date 1 day before the requested date (assuming that the LocalDate field, as a result of it having no time information, is being treated as 00:00:00.

What is the best way to save LocalDates in this situation? Should I be following the advice here https://stackoverflow.com/a/29751575/3832047 and explicitly setting all LocalDate fields to UTC or something similar?

I ran a test to see what happens when converting them in code and got the following result:

Date convertedDate = Date.valueOf(localDate);

conversion-result

EDIT

Here is an example of the code I use to retrieve the data, where the odd date change occurs as well. If I request data for 2017-06-27, I receive results for 2017-06-26.

CriteriaBuilder criteriaBuilder = sessionFactory.getCriteriaBuilder();
CriteriaQuery criteriaQuery = criteriaBuilder.createQuery(HorseAndTrailerRequest.class);
Root<HorseAndTrailerRequest> criteria = criteriaQuery.from(HorseAndTrailerRequest.class);

ParameterExpression<LocalDate> effectiveDateParameter = criteriaBuilder.parameter(LocalDate.class);
    criteriaQuery.select(criteria)
            .where(
                    criteriaBuilder.equal(criteria.get("effectiveDate"), effectiveDateParameter)
            );

TypedQuery<HorseAndTrailerRequest> query = sessionFactory.getCurrentSession().createQuery(criteriaQuery);
query.setParameter(effectiveDateParameter, date);
return query.getResultList();

Answer 1

Since LocalDate has no TimeZone, you can map the column_date as long in your database schema, and use AttributeConverter to convert LocalDate to long to avoid time zone conversion problems :

import javax.persistence.Converter;
import java.time.LocalDate;
import javax.persistence.AttributeConverter;
@Converter
public class LocalDateToLong implements AttributeConverter<LocalDate, Long> {

    @Override
    public Long convertToDatabaseColumn(LocalDate date) {
        if (date != null) {
            long epochDay = date.toEpochDay();
            return epochDay;
        }
        return null;
    }

    @Override
    public LocalDate convertToEntityAttribute(Long epochDay) {
        // TODO Auto-generated method stub
        if (epochDay != null) {
            LocalDate date = LocalDate.ofEpochDay(epochDay);
            return date;
        }
        return null;
    }

}