//$Id: CascadingAction.java 10458 2006-09-06 14:07:22Z epbernard $
package org.hibernate.engine;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.HibernateException;
import org.hibernate.LockMode;
import org.hibernate.ReplicationMode;
import org.hibernate.TransientObjectException;
import org.hibernate.proxy.HibernateProxy;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.collection.PersistentCollection;
import org.hibernate.event.EventSource;
import org.hibernate.type.CollectionType;
import org.hibernate.type.Type;
import org.hibernate.type.EntityType;
/**
* A session action that may be cascaded from parent entity to its children
*
* @author Gavin King
*/
public abstract class CascadingAction {
private static final Log log = LogFactory.getLog( CascadingAction.class );
// the CascadingAction contract ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/**
* protected constructor
*/
CascadingAction() {
}
/**
* Cascade the action to the child object.
*
* @param session The session within which the cascade is occuring.
* @param child The child to which cascading should be performed.
* @param entityName The child's entity name
* @param anything Anything ;) Typically some form of cascade-local cache
* which is specific to each CascadingAction type
* @param isCascadeDeleteEnabled Are cascading deletes enabled.
* @throws HibernateException
*/
public abstract void cascade(
EventSource session,
Object child,
String entityName,
Object anything,
boolean isCascadeDeleteEnabled) throws HibernateException;
/**
* Given a collection, get an iterator of the children upon which the
* current cascading action should be visited.
*
* @param session The session within which the cascade is occuring.
* @param collectionType The mapping type of the collection.
* @param collection The collection instance.
* @return The children iterator.
*/
public abstract Iterator getCascadableChildrenIterator(
EventSource session,
CollectionType collectionType,
Object collection);
/**
* Does this action potentially extrapolate to orphan deletes?
*
* @return True if this action can lead to deletions of orphans.
*/
public abstract boolean deleteOrphans();
/**
* Does the specified cascading action require verification of no cascade validity?
*
* @return True if this action requires no-cascade verification; false otherwise.
*/
public boolean requiresNoCascadeChecking() {
return false;
}
/**
* Called (in the case of {@link #requiresNoCascadeChecking} returning true) to validate
* that no cascade on the given property is considered a valid semantic.
*
* @param session The session witin which the cascade is occurring.
* @param child The property value
* @param parent The property value owner
* @param persister The entity persister for the owner
* @param propertyIndex The index of the property within the owner.
*/
public void noCascade(EventSource session, Object child, Object parent, EntityPersister persister, int propertyIndex) {
}
/**
* Should this action be performed (or noCascade consulted) in the case of lazy properties.
*/
public boolean performOnLazyProperty() {
return true;
}
// the CascadingAction implementations ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/**
* @see org.hibernate.Session#delete(Object)
*/
public static final CascadingAction DELETE = new CascadingAction() {
public void cascade(EventSource session, Object child, String entityName, Object anything, boolean isCascadeDeleteEnabled)
throws HibernateException {
if ( log.isTraceEnabled() ) {
log.trace("cascading to delete: " + entityName);
}
session.delete( entityName, child, isCascadeDeleteEnabled, ( Set ) anything );
}
public Iterator getCascadableChildrenIterator(EventSource session, CollectionType collectionType, Object collection) {
// delete does cascade to uninitialized collections
return CascadingAction.getAllElementsIterator(session, collectionType, collection);
}
public boolean deleteOrphans() {
// orphans should be deleted during delete
return true;
}
public String toString() {
return "ACTION_DELETE";
}
};
/**
* @see org.hibernate.Session#lock(Object, LockMode)
*/
public static final CascadingAction LOCK = new CascadingAction() {
public void cascade(EventSource session, Object child, String entityName, Object anything, boolean isCascadeDeleteEnabled)
throws HibernateException {
if ( log.isTraceEnabled() ) {
log.trace( "cascading to lock: " + entityName );
}
session.lock( entityName, child, LockMode.NONE/*(LockMode) anything*/ );
}
public Iterator getCascadableChildrenIterator(EventSource session, CollectionType collectionType, Object collection) {
// lock doesn't cascade to uninitialized collections
return getLoadedElementsIterator(session, collectionType, collection);
}
public boolean deleteOrphans() {
//TODO: should orphans really be deleted during lock???
return false;
}
public String toString() {
return "ACTION_LOCK";
}
};
/**
* @see org.hibernate.Session#refresh(Object)
*/
public static final CascadingAction REFRESH = new CascadingAction() {
public void cascade(EventSource session, Object child, String entityName, Object anything, boolean isCascadeDeleteEnabled)
throws HibernateException {
if ( log.isTraceEnabled() ) {
log.trace( "cascading to refresh: " + entityName );
}
session.refresh( child, (Map) anything );
}
public Iterator getCascadableChildrenIterator(EventSource session, CollectionType collectionType, Object collection) {
// refresh doesn't cascade to uninitialized collections
return getLoadedElementsIterator(session, collectionType, collection);
}
public boolean deleteOrphans() {
return false;
}
public String toString() {
return "ACTION_REFRESH";
}
};
/**
* @see org.hibernate.Session#evict(Object)
*/
public static final CascadingAction EVICT = new CascadingAction() {
public void cascade(EventSource session, Object child, String entityName, Object anything, boolean isCascadeDeleteEnabled)
throws HibernateException {
if ( log.isTraceEnabled() ) {
log.trace( "cascading to evict: " + entityName );
}
session.evict(child);
}
public Iterator getCascadableChildrenIterator(EventSource session, CollectionType collectionType, Object collection) {
// evicts don't cascade to uninitialized collections
return getLoadedElementsIterator(session, collectionType, collection);
}
public boolean deleteOrphans() {
return false;
}
public boolean performOnLazyProperty() {
return false;
}
public String toString() {
return "ACTION_EVICT";
}
};
/**
* @see org.hibernate.Session#saveOrUpdate(Object)
*/
public static final CascadingAction SAVE_UPDATE = new CascadingAction() {
public void cascade(EventSource session, Object child, String entityName, Object anything, boolean isCascadeDeleteEnabled)
throws HibernateException {
if ( log.isTraceEnabled() ) {
log.trace( "cascading to saveOrUpdate: " + entityName );
}
session.saveOrUpdate(entityName, child);
}
public Iterator getCascadableChildrenIterator(EventSource session, CollectionType collectionType, Object collection) {
// saves / updates don't cascade to uninitialized collections
return getLoadedElementsIterator(session, collectionType, collection);
}
public boolean deleteOrphans() {
// orphans should be deleted during save/update
return true;
}
public boolean performOnLazyProperty() {
return false;
}
public String toString() {
return "ACTION_SAVE_UPDATE";
}
};
/**
* @see org.hibernate.Session#merge(Object)
*/
public static final CascadingAction MERGE = new CascadingAction() {
public void cascade(EventSource session, Object child, String entityName, Object anything, boolean isCascadeDeleteEnabled)
throws HibernateException {
if ( log.isTraceEnabled() ) {
log.trace( "cascading to merge: " + entityName );
}
session.merge( entityName, child, (Map) anything );
}
public Iterator getCascadableChildrenIterator(EventSource session, CollectionType collectionType, Object collection) {
// merges don't cascade to uninitialized collections
// //TODO: perhaps this does need to cascade after all....
return getLoadedElementsIterator(session, collectionType, collection);
}
public boolean deleteOrphans() {
// orphans should not be deleted during merge??
return false;
}
public String toString() {
return "ACTION_MERGE";
}
};
/**
* @see org.hibernate.classic.Session#saveOrUpdateCopy(Object)
*/
public static final CascadingAction SAVE_UPDATE_COPY = new CascadingAction() {
// for deprecated saveOrUpdateCopy()
public void cascade(EventSource session, Object child, String entityName, Object anything, boolean isCascadeDeleteEnabled)
throws HibernateException {
if ( log.isTraceEnabled() ) {
log.trace( "cascading to saveOrUpdateCopy: " + entityName );
}
session.saveOrUpdateCopy( entityName, child, (Map) anything );
}
public Iterator getCascadableChildrenIterator(EventSource session, CollectionType collectionType, Object collection) {
// saves / updates don't cascade to uninitialized collections
return getLoadedElementsIterator(session, collectionType, collection);
}
public boolean deleteOrphans() {
// orphans should not be deleted during copy??
return false;
}
public String toString() {
return "ACTION_SAVE_UPDATE_COPY";
}
};
/**
* @see org.hibernate.Session#persist(Object)
*/
public static final CascadingAction PERSIST = new CascadingAction() {
public void cascade(EventSource session, Object child, String entityName, Object anything, boolean isCascadeDeleteEnabled)
throws HibernateException {
if ( log.isTraceEnabled() ) {
log.trace( "cascading to persist: " + entityName );
}
session.persist( entityName, child, (Map) anything );
}
public Iterator getCascadableChildrenIterator(EventSource session, CollectionType collectionType, Object collection) {
// persists don't cascade to uninitialized collections
return CascadingAction.getAllElementsIterator(session, collectionType, collection);
}
public boolean deleteOrphans() {
return false;
}
public boolean performOnLazyProperty() {
return false;
}
public String toString() {
return "ACTION_PERSIST";
}
};
/**
* Execute persist during flush time
*
* @see org.hibernate.Session#persist(Object)
*/
public static final CascadingAction PERSIST_ON_FLUSH = new CascadingAction() {
public void cascade(EventSource session, Object child, String entityName, Object anything, boolean isCascadeDeleteEnabled)
throws HibernateException {
if ( log.isTraceEnabled() ) {
log.trace( "cascading to persistOnFlush: " + entityName );
}
session.persistOnFlush( entityName, child, (Map) anything );
}
public Iterator getCascadableChildrenIterator(EventSource session, CollectionType collectionType, Object collection) {
// persists don't cascade to uninitialized collections
return CascadingAction.getLoadedElementsIterator(session, collectionType, collection);
}
public boolean deleteOrphans() {
return true;
}
public boolean requiresNoCascadeChecking() {
return true;
}
public void noCascade(
EventSource session,
Object child,
Object parent,
EntityPersister persister,
int propertyIndex) {
if ( child == null ) {
return;
}
Type type = persister.getPropertyTypes()[propertyIndex];
if ( type.isEntityType() ) {
String childEntityName = ( ( EntityType ) type ).getAssociatedEntityName( session.getFactory() );
if ( ! isInManagedState( child, session )
&& ! ( child instanceof HibernateProxy ) //a proxy cannot be transient and it breaks ForeignKeys.isTransient
&& ForeignKeys.isTransient( childEntityName, child, null, session ) ) {
String parentEntiytName = persister.getEntityName();
String propertyName = persister.getPropertyNames()[propertyIndex];
throw new TransientObjectException(
"object references an unsaved transient instance - " +
"save the transient instance before flushing: " +
parentEntiytName + "." + propertyName + " -> " + childEntityName
);
}
}
}
public boolean performOnLazyProperty() {
return false;
}
private boolean isInManagedState(Object child, EventSource session) {
EntityEntry entry = session.getPersistenceContext().getEntry( child );
return entry != null && (entry.getStatus() == Status.MANAGED || entry.getStatus() == Status.READ_ONLY);
}
public String toString() {
return "ACTION_PERSIST_ON_FLUSH";
}
};
/**
* @see org.hibernate.Session#replicate(Object, org.hibernate.ReplicationMode)
*/
public static final CascadingAction REPLICATE = new CascadingAction() {
public void cascade(EventSource session, Object child, String entityName, Object anything, boolean isCascadeDeleteEnabled)
throws HibernateException {
if ( log.isTraceEnabled() ) {
log.trace( "cascading to replicate: " + entityName );
}
session.replicate( entityName, child, (ReplicationMode) anything );
}
public Iterator getCascadableChildrenIterator(EventSource session, CollectionType collectionType, Object collection) {
// replicate does cascade to uninitialized collections
return getLoadedElementsIterator(session, collectionType, collection);
}
public boolean deleteOrphans() {
return false; //I suppose?
}
public String toString() {
return "ACTION_REPLICATE";
}
};
// static helper methods ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/**
* Given a collection, get an iterator of all its children, loading them
* from the database if necessary.
*
* @param session The session within which the cascade is occuring.
* @param collectionType The mapping type of the collection.
* @param collection The collection instance.
* @return The children iterator.
*/
private static Iterator getAllElementsIterator(
EventSource session,
CollectionType collectionType,
Object collection) {
return collectionType.getElementsIterator( collection, session );
}
/**
* Iterate just the elements of the collection that are already there. Don't load
* any new elements from the database.
*/
public static Iterator getLoadedElementsIterator(SessionImplementor session, CollectionType collectionType, Object collection) {
if ( collectionIsInitialized(collection) ) {
// handles arrays and newly instantiated collections
return collectionType.getElementsIterator(collection, session);
}
else {
// does not handle arrays (thats ok, cos they can't be lazy)
// or newly instantiated collections, so we can do the cast
return ( (PersistentCollection) collection ).queuedAdditionIterator();
}
}
private static boolean collectionIsInitialized(Object collection) {
return !(collection instanceof PersistentCollection) || ( (PersistentCollection) collection ).wasInitialized();
}
} |
