/******************************************************************************* | |
* Copyright (c) 1998, 2013 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 org.eclipse.persistence.indirection.*; | |
/** | |
* Used as the backup value holder in the unit of work for transparent indirection. | |
* This ensure that a reference to the original value holder is held in case the | |
* transparent collection or proxy is replace without first instantiating the original. | |
* | |
* @since 10.1.3 | |
* @author James Sutherland | |
*/ | |
public class BackupValueHolder extends ValueHolder { | |
/** Stores the original uow clone's value holder. */ | |
protected ValueHolderInterface unitOfWorkValueHolder; | |
public BackupValueHolder(ValueHolderInterface unitOfWorkValueHolder) { | |
this.unitOfWorkValueHolder = unitOfWorkValueHolder; | |
} | |
/** | |
* If the original value holder was not instantiated, | |
* then first instantiate it to obtain the backup value. | |
*/ | |
public Object getValue() { | |
// Ensures instantiation of the original, and setting of this back value holder's value. | |
getUnitOfWorkValueHolder().getValue(); | |
return value; | |
} | |
/** | |
* Return the original uow clone's value holder. | |
*/ | |
public ValueHolderInterface getUnitOfWorkValueHolder() { | |
return unitOfWorkValueHolder; | |
} | |
} |