Java – JPA Support for Java 8 Date and Time API

javajava-8java-timejpajpa-2.1

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.

Best Answer

For Hibernate 5.X just add

    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-java8</artifactId>
        <version>${hibernate.version}</version>
    </dependency>

and

@NotNull
@Column(name = "date_time", nullable = false)
protected LocalDateTime dateTime;

will work without any additional effort. See https://hibernate.atlassian.net/browse/HHH-8844

UPDATE:

Please have a look at Jeff Morin comment: since Hibernate 5.2.x it is enough

 <dependency>
     <groupId>org.hibernate</groupId>
     <artifactId>hibernate-core</artifactId>
     <version>5.2.1.Final</version>
 </dependency>
 <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-...</artifactId>
     <version>4.3.1.RELEASE</version>
 </dependency>

See https://github.com/hibernate/hibernate-orm/wiki/Migration-Guide---5.2 and Integrate Hibernate 5.2 with Spring framework 4.x

Related Solutions

Java 8 Date & Time API – New Features and Usage

With Java < 8, you would need to write something like:

Calendar cal = Calendar.getInstance();
cal.set(Calendar.HOUR, cal.get(Calendar.HOUR) + 2);

vs. with Java 8:

LocalTime now = LocalTime.now();
LocalTime later = now.plus(2, HOURS);

The improvements are essentially on

readability:
- Calendar.getInstance() is not very well named: it is hard to tell which instance you are getting without reading the Javadoc. LocalTime.now() is quite self-describing: you get a time and it is now.
- To offset a date, you call an offsetting method (plus) whereas with the Calendar API, you have to manually change the fields of the object (in this example, the hour) which is error prone.
ease of use (see for example the table towards the bottom of this page for a comparison):
- the Calendar API is complicated to use because it mixes concepts, such as a simple date (June 26th 2015) and an instant in time (June 26th 2015 at 10am UTC) - there isn't a class for the former concept
- The new Time API has a clear separation between the various date/time concepts
safety:
- The Calendar API is not safe: nothing prevents you from writing cal.set(123, 2) which would throw a not-so-helpful ArrayOutOfBoundsException. The new API uses enums which solves that problem.
- The new API uses immutable objects, which makes it thread safe.

Overall, the new API is significantly inspired from jodatime which has been the preferred Java Date API for quite some time now. You can also read this detailed comparison of Java (<1.8) date vs. JodaTime (most of it should apply to the Java 8 Date API).

Java 8 LocalDateTime with JPA and Hibernate – How to Use

For any Hibernate 5.x users, there is

<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-java8</artifactId>
    <version>5.0.0.Final</version>
</dependency>

You don't need to do anything else. Just add the dependency, and the Java 8 time types should work like any other basic types, no annotations required.

private LocalDateTime invalidateTokenDate;

Note: this won't save to timestamp type though. Testing with MySQL, it saves to datetime type.

Best Answer

Related Solutions

Java 8 Date & Time API – New Features and Usage

Java 8 LocalDateTime with JPA and Hibernate – How to Use

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