org.egov.infra.config.persistence.event.listener

Class HibernateEventListener

java.lang.Object

org.egov.infra.config.persistence.event.listener.HibernateEventListener

All Implemented Interfaces:

Serializable, org.hibernate.event.spi.PreUpdateEventListener, org.hibernate.event.spi.SaveOrUpdateEventListener

public class HibernateEventListener
extends Object
implements org.hibernate.event.spi.SaveOrUpdateEventListener, org.hibernate.event.spi.PreUpdateEventListener

This Event listener class sets the audit properties createdBy, createdDate modifiedBy and modifiedDate. It does this by hooking to the pre-update and pre-insert events. The pre-update event was chosen instead of save-update events for setting modified properties to fix a bug where even for object reads the Hibernate objects were getting updated. However, the save-update event is still required for new objects (inserts) as Hibernate checks for not-null constraints before the pre-update event is fired. Due to auto flushing strategy that we use, every transaction commit causes a session.flush to be called. Flush calls cascade of collections or properties which fires the save-update event if cascade value is anything other than Cascade.NONE.

Author:

sahinab

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
HibernateEventListener()

Method Summary

Modifier and Type	Method and Description
boolean	onPreUpdate(org.hibernate.event.spi.PreUpdateEvent event) Sets the modifiedBy and modifiedDate properties on objects that inherit from BaseModel.
void	onSaveOrUpdate(org.hibernate.event.spi.SaveOrUpdateEvent event) For new objects that are created, this event is used to set the audit properties.

Methods inherited from class java.lang.Object

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

Constructor Detail

HibernateEventListener

public HibernateEventListener()

Method Detail

onPreUpdate

public boolean onPreUpdate(org.hibernate.event.spi.PreUpdateEvent event)

Sets the modifiedBy and modifiedDate properties on objects that inherit from BaseModel. event.getState() is used to get the list of properties for the object as these are the properties that Hibernate generates the UPDATE statement for. A separate session is used to get the User object to ensure that the object thus obtained is flushed from within the event. @ return false to continue the processing

Specified by:

onPreUpdate in interface org.hibernate.event.spi.PreUpdateEventListener

onSaveOrUpdate

public void onSaveOrUpdate(org.hibernate.event.spi.SaveOrUpdateEvent event)

For new objects that are created, this event is used to set the audit properties. This is done here instead of the pre-insert event because Hibernate checks for not-null constraints before the pre-update and pre-insert are fired.

Specified by:

onSaveOrUpdate in interface org.hibernate.event.spi.SaveOrUpdateEventListener