package org.apache.ojb.broker.util.collections;
/* Copyright 2003-2005 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import org.apache.ojb.broker.PersistenceBroker;
import org.apache.ojb.broker.PersistenceBrokerException;
import org.apache.ojb.broker.metadata.ClassDescriptor;
import java.util.Iterator;
import java.util.Vector;
/**
* This is a collection that tracks removal and addition of elements.
* This tracking allow the PersistenceBroker to delete elements from
* the database that have been removed from the collection before a
* PB.store() orperation occurs.
* This will allow to use the PB api in way pretty close to ODMG persistent
* collections!
* @author Thomas Mahler
* @version $Id: RemovalAwareCollection.java,v 1.7.2.3 2005/12/21 22:28:15 tomdz Exp $
*/
public class RemovalAwareCollection extends ManageableVector implements IRemovalAwareCollection
{
private Vector allObjectsToBeRemoved = new Vector();
/**
* @see org.apache.ojb.broker.ManageableCollection#afterStore(PersistenceBroker broker)
*/
public void afterStore(PersistenceBroker broker) throws PersistenceBrokerException
{
// make sure allObjectsToBeRemoved does not contain
// any instances that got re-added to the list
allObjectsToBeRemoved.removeAll(this);
Iterator iter = allObjectsToBeRemoved.iterator();
while (iter.hasNext())
{
Object obj = iter.next();
ClassDescriptor cld = broker.getClassDescriptor(obj.getClass());
if (broker.serviceBrokerHelper().assertValidPkForDelete(cld, obj))
{
broker.delete(obj);
}
}
allObjectsToBeRemoved.clear();
}
/**
* @see java.util.List#remove(int)
*/
public Object remove(int index)
{
Object toBeRemoved = super.remove(index);
registerForDeletion(toBeRemoved);
return toBeRemoved;
}
protected void registerForDeletion(Object toBeRemoved)
{
//only add objects once to avoid double deletions
if (!allObjectsToBeRemoved.contains(toBeRemoved))
{
this.allObjectsToBeRemoved.add(toBeRemoved);
}
}
/**
* @see java.util.Collection#remove(Object)
*/
public boolean remove(Object o)
{
boolean result = super.remove(o);
registerForDeletion(o);
return result;
}
/**
* @see java.util.Vector#clear()
*/
public synchronized void clear()
{
removeAllElements();
}
/**
* @see java.util.Vector#removeAllElements()
*/
public synchronized void removeAllElements()
{
for (int i = 0; i < this.size(); i++)
{
registerForDeletion(this.get(i));
}
super.removeAllElements();
}
/**
* @see java.util.Vector#removeElementAt(int)
*/
public synchronized void removeElementAt(int index)
{
Object toBeDeleted = this.get(index);
registerForDeletion(toBeDeleted);
super.removeElementAt(index);
}
/**
* @see java.util.AbstractList#removeRange(int, int)
*/
protected void removeRange(int fromIndex, int toIndex)
{
for (int i = fromIndex; i < toIndex; i++)
{
registerForDeletion(this.get(i));
}
super.removeRange(fromIndex, toIndex);
}
}