/*******************************************************************************
* Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.internal.indirection;
import java.util.Collection;
import org.eclipse.persistence.descriptors.ClassDescriptor;
import org.eclipse.persistence.indirection.*;
import org.eclipse.persistence.internal.sessions.AbstractRecord;
import org.eclipse.persistence.internal.sessions.UnitOfWorkImpl;
import org.eclipse.persistence.mappings.*;
/**
* UnitOfWorkQueryValueHolder wraps a database-stored object and
* implements behavior to access it. The object is read from
* the database by invoking a user-specified query.
* This value holder is used only in the unit of work.
*
* @author Sati
*/
public class UnitOfWorkQueryValueHolder extends UnitOfWorkValueHolder {
protected UnitOfWorkQueryValueHolder() {
super();
}
protected UnitOfWorkQueryValueHolder(ValueHolderInterface attributeValue, Object clone, DatabaseMapping mapping, UnitOfWorkImpl unitOfWork) {
super(attributeValue, clone, mapping, unitOfWork);
}
public UnitOfWorkQueryValueHolder(ValueHolderInterface attributeValue, Object clone, ForeignReferenceMapping mapping, AbstractRecord row, UnitOfWorkImpl unitOfWork) {
this(attributeValue, clone, mapping, unitOfWork);
this.row = row;
}
/**
* Backup the clone attribute value.
*/
protected Object buildBackupCloneFor(Object cloneAttributeValue) {
return this.mapping.buildBackupCloneForPartObject(cloneAttributeValue, null, null, getUnitOfWork());
}
/**
* Clone the original attribute value.
*/
public Object buildCloneFor(Object originalAttributeValue) {
Integer refreshCascade = null;
if (wrappedValueHolder instanceof QueryBasedValueHolder){
refreshCascade = ((QueryBasedValueHolder)getWrappedValueHolder()).getRefreshCascadePolicy();
}
Object clone = this.mapping.buildCloneForPartObject(originalAttributeValue, null, null, this.relationshipSourceObject, getUnitOfWork(), refreshCascade, true, true);
// Bug 414801
if (wrappedValueHolder.isInstantiated() && refreshCascade != null) {
((QueryBasedValueHolder)getWrappedValueHolder()).setRefreshCascadePolicy(null);
}
return clone;
}
/**
* Ensure that the backup value holder is populated.
*/
public void setValue(Object theValue) {
// Must force instantiation to be able to compare with the old value.
if (!this.isInstantiated) {
instantiate();
}
Object oldValue = getValue();
super.setValue(theValue);
updateForeignReferenceSet(theValue, oldValue);
}
/**
* INTERNAL:
* Here we now must check for bi-directional relationship.
* If the mapping has a relationship partner then we must maintain the original relationship.
* We only worry about ObjectReferenceMappings as the collections mappings will be handled by transparentIndirection
*/
public void updateForeignReferenceRemove(Object value) {
DatabaseMapping sourceMapping = this.getMapping();
if (sourceMapping == null) {
//mapping is a transient attribute. If it does not exist then we have been serialized
return;
}
if (sourceMapping.isPrivateOwned()) {
// don't null out backpointer on private owned relationship because it will cause an
// extra update.
return;
}
// ForeignReferenceMapping partner = (ForeignReferenceMapping)getMapping().getRelationshipPartner();
ForeignReferenceMapping partner = this.getRelationshipPartnerFor(value);
if (partner != null) {
if (value != null) {
Object unwrappedValue = partner.getDescriptor().getObjectBuilder().unwrapObject(value, getSession());
Object oldParent = partner.getRealAttributeValueFromObject(unwrappedValue, getSession());
Object sourceObject = getRelationshipSourceObject();
if (oldParent == null) {
// value has already been set
return;
}
// PERF: If the collection is not instantiated, then do not instantiated it.
if (partner.isCollectionMapping()) {
if ((!(oldParent instanceof IndirectContainer)) || ((IndirectContainer)oldParent).isInstantiated()) {
if (!partner.getContainerPolicy().contains(sourceObject, oldParent, getSession())) {
// value has already been set
return;
}
}
}
if (partner.isObjectReferenceMapping()) {
// Check if it's already been set to null
partner.setRealAttributeValueInObject(unwrappedValue, null);
} else if (partner.isCollectionMapping()) {
// If it is not in the collection then it has already been removed.
partner.getContainerPolicy().removeFrom(sourceObject, oldParent, getSession());
}
}
}
}
/**
* INTERNAL:
* Here we now must check for bi-directional relationship.
* If the mapping has a relationship partner then we must maintain the original relationship.
* We only worry about ObjectReferenceMappings as the collections mappings will be handled by transparentIndirection
*/
public void updateForeignReferenceSet(Object value, Object oldValue) {
if ((value != null) && (value instanceof Collection)) {
//I'm passing a collection into the valueholder not an object
return;
}
if (getMapping() == null) {
//mapping is a transient attribute. If it does not exist then we have been serialized
return;
}
// ForeignReferenceMapping partner = (ForeignReferenceMapping)getMapping().getRelationshipPartner();
ForeignReferenceMapping partner = this.getRelationshipPartnerFor(value);
if (partner != null) {
if (value != null) {
Object unwrappedValue = partner.getDescriptor().getObjectBuilder().unwrapObject(value, getSession());
Object oldParent = partner.getRealAttributeValueFromObject(unwrappedValue, getSession());
Object sourceObject = getRelationshipSourceObject();
Object wrappedSource = getMapping().getDescriptor().getObjectBuilder().wrapObject(sourceObject, getSession());
if (oldParent == sourceObject) {
// value has already been set
return;
}
// PERF: If the collection is not instantiated, then do not instantiated it.
if (partner.isCollectionMapping()) {
if ((!(oldParent instanceof IndirectContainer)) || ((IndirectContainer)oldParent).isInstantiated()) {
if (partner.getContainerPolicy().contains(sourceObject, oldParent, getSession())) {
// value has already been set
return;
}
}
}
// Set the Object that was referencing this value to reference null, or remove value from its collection
if (oldParent != null) {
if (getMapping().isObjectReferenceMapping()) {
if (!partner.isCollectionMapping()) {
// If the back pointer is a collection it's OK that I'm adding myself into the collection
((ObjectReferenceMapping)getMapping()).setRealAttributeValueInObject(oldParent, null);
}
} else if (getMapping().isCollectionMapping() && (!partner.isManyToManyMapping())) {
getMapping().getContainerPolicy().removeFrom(unwrappedValue, getMapping().getRealAttributeValueFromObject(oldParent, getSession()), getSession());
}
}
if (oldValue != null) {
// CR 3487
Object unwrappedOldValue = partner.getDescriptor().getObjectBuilder().unwrapObject(oldValue, getSession());
// if this object was referencing a different object reset the back pointer on that object
if (partner.isObjectReferenceMapping()) {
partner.setRealAttributeValueInObject(unwrappedOldValue, null);
} else if (partner.isCollectionMapping()) {
partner.getContainerPolicy().removeFrom(sourceObject, partner.getRealAttributeValueFromObject(unwrappedOldValue, getSession()), getSession());
}
}
// Now set the back reference of the value being passed in to point to this object
if (partner.isObjectReferenceMapping()) {
partner.setRealAttributeValueInObject(unwrappedValue, wrappedSource);
} else if (partner.isCollectionMapping()) {
partner.getContainerPolicy().addInto(wrappedSource, oldParent, getSession());
}
} else {
updateForeignReferenceRemove(oldValue);
}
}
}
/**
* Helper method to retrieve the relationship partner mapping. This will take inheritance
* into account and return the mapping associated with correct subclass if necessary. This
* is needed for EJB 2.0 inheritance
*/
private ForeignReferenceMapping getRelationshipPartnerFor(Object partnerObject) {
ForeignReferenceMapping partner = (ForeignReferenceMapping)getMapping().getRelationshipPartner();
if ((partner == null) || (partnerObject == null)) {
// no partner, nothing to do
return partner;
}
// if the target object is not an instance of the class type associated with the partner
// mapping, try and look up the same partner mapping but as part of the partnerObject's
// descriptor. Only check if inheritance is involved...
if (partner.getDescriptor().hasInheritance()) {
ClassDescriptor partnerObjectDescriptor = this.getSession().getDescriptor(partnerObject);
if (!(partner.getDescriptor().getJavaClass().isAssignableFrom(partnerObjectDescriptor.getJavaClass()))) {
return (ForeignReferenceMapping)partnerObjectDescriptor.getObjectBuilder().getMappingForAttributeName(partner.getAttributeName());
}
}
return partner;
}
}