| /*************************************************************************** |
| * Copyright (c) 2004 - 2008 Martin Taal and others |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * Martin Taal - copied from CDORevisionPropertyHandler and adapted |
| **************************************************************************/ |
| package org.eclipse.emf.cdo.server.internal.hibernate.tuplizer; |
| |
| import org.eclipse.emf.cdo.common.revision.CDOList; |
| import org.eclipse.emf.cdo.spi.common.InternalCDORevision; |
| |
| import org.hibernate.HibernateException; |
| import org.hibernate.collection.PersistentCollection; |
| |
| /** |
| * @author Martin Taal |
| */ |
| // Howto handle hibernate lists: |
| // - a new owner: the owner is persisted and its lists are replaced with hibernate |
| // persistentlist, the hibernate persitentlist will have a delegate (internally) which is the list which was previously |
| // present in the owner. |
| // - an existing owner: the owner is read from the db and hibernate will set a persistentlist |
| // directly |
| // |
| // The solution also needs to handle the following: |
| // - cdo does not have direct java references but stores cdoids in the list while hibernate expects real java object |
| // references. |
| // - cdo uses a moveablearraylist and not the standard arraylist |
| // |
| // The solution: |
| // - never return null when hibernate asks for the current value of the manyreference, always |
| // return a MoveableArrayList so that hibernate uses that as the delegate, set the MoveableArrayList |
| public class CDOManyReferenceGetter extends CDOPropertyGetter |
| { |
| private static final long serialVersionUID = 1L; |
| |
| public CDOManyReferenceGetter(CDORevisionTuplizer tuplizer, String propertyName) |
| { |
| super(tuplizer, propertyName); |
| } |
| |
| @Override |
| public Object get(Object target) throws HibernateException |
| { |
| // Check if there is already a persistentcollection |
| PersistentCollection collection = PersistableListHolder.getInstance().getListMapping(target, getCDOFeature()); |
| if (collection != null) |
| { |
| return collection; |
| } |
| |
| InternalCDORevision revision = (InternalCDORevision)target; |
| CDOList list = revision.getList(getCDOFeature(), 10); |
| |
| // Wrap the moveablearraylist |
| HibernateMoveableListWrapper wrapper = new HibernateMoveableListWrapper(); |
| wrapper.setDelegate(list); |
| |
| // And return it |
| return wrapper; |
| } |
| } |