Differences between JPA and JPA2

Question

Does anyone have a list of the changes between JPA 1 and JPA 2? I have read about the Criteria queries and other changes, but I would like a "what's new" kind of reference. Thanks

Answer 1

Google returns many results, including this and this blog posts. The summary (copied from the former) is:

• Added support for persistently ordered lists using OrderColumn and provider-managed ordering column
• Defined support for foreign key mapping strategy for unidirectional one-to-many relationships
• Added clear method to EntityManager interface to allow entities to be evicted from the persistence context; added CLEAR cascade option.
• Added Cache interface.
• Added support for pessimistic locking and new lock mode types.
• Added overloaded find and refresh methods added to support locking with standardized and vendor-specific properties and hints.
• Added standardized hint javax.persistence.lock.timeout for use in locking configuration.
• Added the standardized properties javax.persistence.jdbc.driver, javax.persistence.jdbc.url, javax.persistence.jdbc.user, javax.persistence.jdbc.password for use in persistence unit and entity manager factory configuration.
• Added Query getNamedParameters and getPositionalParameters methods.

Answer 2

JPA2 also adds typesafe query api. see http://www.ibm.com/developerworks/java/library/j-typesafejpa/

Answer 3

There is also a pdf version of Mike Keith's presentation "What's New and Exciting in JPA 2.0" from Jazoon 2009.