org.springframework.orm.hibernate3.support
Class IdTransferringMergeEventListener

java.lang.Object
  DefaultMergeEventListener
      org.springframework.orm.hibernate3.support.IdTransferringMergeEventListener

public class IdTransferringMergeEventListener
extends DefaultMergeEventListener

Extension of Hibernate's DefaultMergeEventListener, transferring the ids of newly saved objects to the corresponding original objects (that are part of the detached object graph passed into the merge method).

Transferring newly assigned ids to the original graph allows for continuing to use the original object graph, despite merged copies being registered with the current Hibernate Session. This is particularly useful for web applications that might want to store an object graph and then render it in a web view, with links that include the id of certain (potentially newly saved) objects.

The merge behavior given by this MergeEventListener is nearly identical to TopLink's merge behavior. See PetClinic for an example, which relies on ids being available for newly saved objects: the HibernateClinic and TopLinkClinic DAO implementations both use straight merge calls, with the Hibernate SessionFactory configuration specifying an IdTransferringMergeEventListener.

Typically specified as entry for LocalSessionFactoryBean's "eventListeners" map, with key "merge".

Since:

1.2

Author:

Juergen Hoeller

See Also:

LocalSessionFactoryBean.setEventListeners(java.util.Map)

Constructor Summary

IdTransferringMergeEventListener()

Method Summary

protected void

entityIsTransient(MergeEvent event, java.util.Map copyCache) Hibernate 3.1 implementation of ID transferral.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

IdTransferringMergeEventListener

public IdTransferringMergeEventListener()

Method Detail

entityIsTransient

protected void entityIsTransient(MergeEvent event,
                                 java.util.Map copyCache)

Hibernate 3.1 implementation of ID transferral.