Wednesday Aug 20, 2014

Using the Java SE 8 Date Time API with JPA 2.1

Most of you are hopefully aware of the new Date Time API included in Java SE 8. If you are not, you should check them out right now using the Java Tutorial Trail dedicated to the topic. It is a significantly leap forward in processing temporal data in Java. For those who already use Joda-Time the changes will look very familiar - very simplistically speaking the Java SE 8 feature is basically Joda-Time standardized.

Quite naturally you will likely want to use the new Date Time APIs in your JPA domain model to better represent temporal data. The problem is that JPA 2.1 will not support the new API out of the box. So what are you to do? Fortunately you can make use of fairly simple JPA 2.1 Type Converters to use the Date Time API in your JPA domain classes. Steven Gertiser shows you how to do it in an extremely well written blog entry. Besides explaining the problem and the solution the entry is actually very good for getting a better understanding of JPA 2.1 Type Converters as well. I think such a set of converters may be a good fit for Apache DeltaSpike as a Java EE 7 extension?

In case you are wondering about Java SE 8 support in the JPA specification itself, Nick Williams has already entered an excellent, well researched JIRA entry asking for such support in a future version of the JPA specification that's well worth looking at. Another possibility of course is for JPA providers to start supporting the Date Time API natively before anything is formalized in the specification. What do you think?