Java 8 Date Time api in JPA - spring

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.

Answer 2

To query temporal fields you should use the #Temporal Anotation in the temporal fields, add the converters to persistence.xml and also be sure you are using the java.sql.Date,java.sql.Time or java.sql.Timestamp in the converters. (Sometimes i imported from the wrong package)
for example thats works for me:
#Temporal(TemporalType.TIMESTAMP)
#Convert(converter = InstantPersistenceConverter.class)
private Instant StartInstant;
#Temporal(TemporalType.TIME)
#Convert(converter = LocalTimePersistenceConverter.class)
private LocalTime StartTime;
and my Instant converter:
#Converter(autoApply = true)
public class InstantPersistenceConverter implements AttributeConverter <Instant,java.sql.Timestamp>{
#Override
public java.sql.Timestamp convertToDatabaseColumn(Instant entityValue) {
return java.sql.Timestamp.from(entityValue);
}
#Override
public Instant convertToEntityAttribute(java.sql.Timestamp databaseValue) {
return databaseValue.toInstant();
}
}

Answer 3

Did you add LocalDatePersistenceConverter and LocalDateTimePersistenceConverter in persistence.xml placed in 'class' element ?