Difference between revisions of "EclipseLink/Examples/JPA/Migration/OpenJPA/PersistenceXML"

Revision as of 04:34, 3 November 2009

Migration from OpenJPA to EclipseLink: Persistence XML

NOTE: Under Construction

When migrating it is important to first address the changes required in the persistence.XML file. If you encounter any migration issues in the persistence.xml file not covered here or incomplete please log a documentation enhancement request referencing this page and describe your migration challenge.

Provider

The JPA persistence provider typically needs to be set during any migration to ensure the EclipseLink JPA provider is used in case multiple providers exist in the target container.

<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>

JavaSE USage

It has been reported that in JavaSE usage of OpenJPA the provider resolver functionality may continue to use OpenJPA if it is encountered first on the classpath and ignore the specified <provider>. If this is encountered the best solution is to remove OpenJPA from the classpath of your application or test harness.

PU Properties

Persistence Unit properties are a standard mechanism for providing vendor specific configuration. They are most common used to handle the configuration of:

• JDBC pooling
• Cache configuration and usage

The following table captures the OpneJPA persistence unit properties and their corresponding EclipseLink JPA properties.

NOTE: This is complex mapping task requiring knowledge of both solutions. Not all properties will have a direct mapping.

Please refer to the [[Using_EclipseLink_JPA_Extensions_%28ELUG%29 EclipseLink UserGuide (ELUG)]'s extended JPA functionality for a description of all supported properties or see the PersistenceUnitProperties JavaDocs.