JPA support for Java 8 new date and time API

Question

I'm using Java 8 for my new project.

I'm trying to use new date and time api in java 8 however I don't know if JPA 2.1 fully supports this new Date and Time API or not.

Please share your experience/opinion in JPA`s supports for new date and time API in Java 8.

Can I use new date and time api in Java 8 safely with JPA 2.1?

UPDATE:

I'm using Hibernate (4.3.5.Final) as JPA implementation.

Answer 1

I know that this is an old question but I thought of an alternative solution which might be helpful.

Instead of trying to map the new java.time.* classes to an existing database types, you can leverage @Transient:

@Entity
public class Person {
    private Long id;        
    private Timestamp createdTimestamp;

    @Id
    @GeneratedValue
    public Long getId() { return id; }

    private Timestamp getCreatedTimestamp() {
        return createdTime;
    }

    private void setCreatedTimestamp(final Timestamp ts) {
        this.createdTimestamp = ts;
    }

    @Transient
    public LocalDateTime getCreatedDateTime() {
        return createdTime.getLocalDateTime();
    }

    public void setCreatedDateTime(final LocalDateTime dt) {
        this.createdTime = Timestamp.valueOf(dt);
    }
}

You work with the public getter/setter methods that use the new Java 8 date/time classes, but behind the scenes the getter/setters work with the legacy date/time classes. When you persist the entity, the legacy date/time property will be persisted but not the new Java 8 property since it's annotated with @Transient.

Answer 2

org.jadira.usertype can be used to persist JSR 310 Date and Time API.

Check out this example project.

From Example Project,

@MappedSuperclass
public class AbstractEntity {

    @Id @GeneratedValue Long id;

    @CreatedDate//
    @Type(type = "org.jadira.usertype.dateandtime.threeten.PersistentZonedDateTime")//
    ZonedDateTime createdDate;

    @LastModifiedDate//
    @Type(type = "org.jadira.usertype.dateandtime.threeten.PersistentZonedDateTime")//
    ZonedDateTime modifiedDate;
}

Answer 3

JPA 2.2 supports java.time

JPA 2.2 now supports LocalDate, LocalTime, LocalDateTime, OffsetTime and OffsetDateTime.

<dependency>
  <groupId>javax.persistence</groupId>
  <artifactId>javax.persistence-api</artifactId>
  <version>2.2</version>
</dependency>

For JPA 2.2 implementation, Hibernate 5.2 or EclipseLink 2.7 can be used.

Hibernate 5 supports more java types than JPA 2.2 like Duration, Instant and ZonedDateTime.

More Info:

• How To Map The Date And Time API with JPA 2.2 by Thorben Janssen
• What’s new in JPA 2.2
• JSR 338 (Maintenance Release)
• JPA 2.2 Wiki

Answer 4

I am using Java 8, EclipseLink(JPA 2.1),PostgreSQL 9.3 and PostgreSQL Driver -Postgresql-9.2-1002.jdbc4.jar in my project and i can use LocalDateTime variables from the new API with no problem but the data type of the column is bytea in the database, so you only can read it from a Java aplication as far i know. You can use AttributeConverter to convert the new classes to java.sql.Date I find this code from Java.net

@Converter(autoApply = true)
public class LocalDatePersistenceConverter implements
AttributeConverter {
@Override
public java.sql.Date convertToDatabaseColumn(LocalDate entityValue) {
    return java.sql.Date.valueOf(entityValue);
}

@Override
public LocalDate convertToEntityAttribute(java.sql.Date databaseValue) {
    return databaseValue.toLocalDate();
}

Answer 5

There are Many approach to do , Also It depends to your frame work : If your frame work has on field Converter such spring do such: 1-

@DateTimeFormat(pattern = "dd.MM.yyyy - HH:mm")
private Long createdDate;

here I am using legacy epoch format https://www.epochconverter.com/ epoch is very flexible and accepted format

2- The other ways is to use jpa @PostLoad @PreUpdate @PrePersist

@PostLoad
      public void convert() {
        this.jva8Date= LocalDate.now().plusDays(1);
      }

or use temp one such

@Transient
public LocalDateTime getCreatedDateTime() {
    return createdTime.getLocalDateTime();
}

Answer 6

For type TIMESTAMP you can use this converter:

@Converter(autoApply = true)
public class LocalDateTimeAttributeConverter implements AttributeConverter<LocalDateTime, Timestamp> {

    @Override
    public Timestamp convertToDatabaseColumn(LocalDateTime datetime) {
        return datetime == null ? null : Timestamp.valueOf(datetime);
    }

    @Override
    public LocalDateTime convertToEntityAttribute(Timestamp timestamp) {
        return timestamp == null ? null : timestamp.toLocalDateTime();
    }

}

For type DATE you can use this converter:

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

    @Override
    public Date convertToDatabaseColumn(LocalDate date) {
        return date == null ? null : Date.valueOf(date);
    }

    @Override
    public LocalDate convertToEntityAttribute(Date date) {
        return date == null ? null : date.toLocalDate();
    }

}

For type TIME you can use this converter:

@Converter(autoApply = true)
public class LocalTimeAttributeConverter implements AttributeConverter<LocalTime, Time> {

    @Override
    public Time convertToDatabaseColumn(LocalTime time) {
        return time == null ? null : Time.valueOf(time);
    }

    @Override
    public LocalTime convertToEntityAttribute(Time time) {
        return time == null ? null : time.toLocalTime();
    }

}