IdTransferringMergeEventListener

Class Overview

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".

Summary

[Expand] Inherited Methods
From class java.lang.Object Object clone() boolean equals(Object arg0) void finalize() final Class<?> getClass() int hashCode() final void notify() final void notifyAll() String toString() final void wait() final void wait(long arg0, int arg1) final void wait(long arg0)