Java 8 Date Time api in JPA

Question

What is the best way how to integrate Java 8 Date Time api in jpa?

I have added converters:

@Converter(autoApply = true)
public class LocalDatePersistenceConverter implements AttributeConverter<LocalDate, Date> {

    @Override
    public Date convertToDatabaseColumn(LocalDate localDate) {
        return Date.valueOf(localDate);
    }

    @Override
    public LocalDate convertToEntityAttribute(Date date) {
        return date.toLocalDate();
    }
}

and

@Converter(autoApply = true)
public class LocalDateTimePersistenceConverter implements AttributeConverter<LocalDateTime, Timestamp> {
    @Override
    public Timestamp convertToDatabaseColumn(LocalDateTime entityValue) {
        return Timestamp.valueOf(entityValue);
    }

    @Override
    public LocalDateTime convertToEntityAttribute(Timestamp databaseValue) {
        return databaseValue.toLocalDateTime();
    }
}

Everything seems fine, but how should I use JPQL for querying? I am using Spring JPARepository, and goal is to select all entities where date is the same as date given, only difference is that it is saved in entity as LocalDateTime.

So:

public class Entity  {

    private LocalDateTime dateTime;

    ...
}

And:

@Query("select case when (count(e) > 0) then true else false end from Entity e where e.dateTime = :date")
public boolean check(@Param("date") LocalDate date);

When executing it just gives me exception, which is correct.

Caused by: java.lang.IllegalArgumentException: Parameter value [2014-01-01] did not match expected type [java.time.LocalDateTime (n/a)]

I have tried many ways, but it seems that none is working, is that even possible?

Answer 1

Hibernate has an extension library, hibernate-java8 I believe, which natively supports many of the time types.

You should use it before writing converters.

in hibernate 5.2 you won't need this additional library, it is part of core.