## org.springframework.orm.hibernate3.support
Class IdTransferringMergeEventListener

    java.lang.Object
      org.hibernate.event.def.AbstractReassociateEventListener
          org.hibernate.event.def.AbstractSaveEventListener
              org.hibernate.event.def.DefaultMergeEventListener
                  org.springframework.orm.hibernate3.support.IdTransferringMergeEventListener

All Implemented Interfaces:
  Serializable, MergeEventListener

    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)`, Serialized Form

Field Summary

Fields inherited from class org.hibernate.event.def.AbstractSaveEventListener
`DELETED, DETACHED, PERSISTENT, TRANSIENT`

Constructor Summary
`IdTransferringMergeEventListener()`

Method Summary
`protected void` `entityIsTransient(MergeEvent event, Map copyCache)` Hibernate 3.1 implementation of ID transferral.

Methods inherited from class org.hibernate.event.def.DefaultMergeEventListener
`cascadeAfterSave, cascadeBeforeSave, cascadeOnMerge, copyValues, copyValues, entityIsDetached, entityIsPersistent, getAssumedUnsaved, getCascadeAction, getMergeMap, onMerge, onMerge`

Methods inherited from class org.hibernate.event.def.AbstractSaveEventListener
`getEntityState, getLoggableName, invokeSaveLifecycle, isVersionIncrementDisabled, performSave, performSaveOrReplicate, saveWithGeneratedId, saveWithRequestedId, substituteValuesIfNecessary, validate, visitCollectionsBeforeSave`

Methods inherited from class org.hibernate.event.def.AbstractReassociateEventListener
`reassociate`

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,
                                     Map copyCache)

  Hibernate 3.1 implementation of ID transferral.

  Overrides:
    `entityIsTransient` in class `DefaultMergeEventListener`