/**********************************************************************
Copyright (c) 2006 Andy Jefferson and others. All rights reserved.
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.
Contributors:
...
**********************************************************************/
package org.jpox.store.fieldmanager;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import org.jpox.ObjectManager;
import org.jpox.ObjectManagerHelper;
import org.jpox.StateManager;
import org.jpox.FetchPlan.FetchPlanForClass;
import org.jpox.api.ApiAdapter;
import org.jpox.sco.SCO;
import org.jpox.state.FetchPlanState;
/**
* Field Manager to handle loading all fields of all objects in the fetch plan.
* The method in StateManagerImpl only loads the fields for that object and so
* will only load the DFG fields for objects (hence omitting any non-DFG fields
* that are in the FetchPlan that have been omitted due to lazy-loading).
*
* @version $Revision: 1.7 $
**/
public class LoadFieldManager extends AbstractFetchFieldManager
{
/**
* Constructor for a field manager for make transient process.
* @param sm the StateManager of the instance being loaded
* @param secondClassMutableFields The second class mutable fields for the class of this object
* @param fpClass Fetch Plan for the class of this instance
* @param state State object to hold any pertinent controls for the fetchplan process
*/
public LoadFieldManager(StateManager sm, boolean[] secondClassMutableFields, FetchPlanForClass fpClass, FetchPlanState state)
{
super(sm, secondClassMutableFields, fpClass, state);
}
/**
* Utility method to process the passed persistable object.
* @param pc The PC object
*/
protected void processPersistable(Object pc)
{
ObjectManager om = ObjectManagerHelper.getObjectManager(pc);
if (om != null)
{
// Field is persisted (otherwise it may have not been persisted by reachability)
om.findStateManager(pc).loadFieldsInFetchPlan(state);
}
}
/**
* Method to fetch an object field whether it is SCO collection, PC, or whatever for the fetchplan process.
* @param fieldNumber Number of the field
* @return The object
*/
protected Object internalFetchObjectField(int fieldNumber)
{
SingleValueFieldManager sfv = new SingleValueFieldManager();
sm.provideFields(new int[]{fieldNumber}, sfv);
Object value = sfv.fetchObjectField(fieldNumber);
ApiAdapter api = sm.getObjectManager().getApiAdapter();
if (value != null)
{
if (api.isPersistable(value))
{
// Process PC fields
processPersistable(value);
}
else if (value instanceof Collection)
{
// Process all elements of the Collection that are PC
if (!(value instanceof SCO))
{
// Replace with SCO
value = sm.wrapSCOField(fieldNumber, value, false, false, true);
}
Collection coll = (Collection)value;
Iterator iter = coll.iterator();
while (iter.hasNext())
{
Object element = iter.next();
if (api.isPersistable(element))
{
processPersistable(element);
}
}
}
else if (value instanceof Map)
{
// Process all keys, values of the Map that are PC
if (!(value instanceof SCO))
{
// Replace with SCO
value = sm.wrapSCOField(fieldNumber, value, false, false, true);
}
Map map = (Map)value;
// Process any keys that are PersistenceCapable
Set keys = map.keySet();
Iterator iter = keys.iterator();
while (iter.hasNext())
{
Object mapKey = iter.next();
if (api.isPersistable(mapKey))
{
processPersistable(mapKey);
}
}
// Process any values that are PersistenceCapable
Collection values = map.values();
iter = values.iterator();
while (iter.hasNext())
{
Object mapValue = iter.next();
if (api.isPersistable(mapValue))
{
processPersistable(mapValue);
}
}
}
else if (value instanceof Object[])
{
Object[] array = (Object[]) value;
for (int i=0;i<array.length;i++)
{
Object element = array[i];
if (api.isPersistable(element))
{
processPersistable(element);
}
}
}
}
return value;
}
/**
* Method called when were arrive at the end of a branch
* @param fieldNumber Number of the field
* @return Object to return
*/
protected Object endOfGraphOperation(int fieldNumber)
{
SingleValueFieldManager sfv = new SingleValueFieldManager();
sm.provideFields(new int[]{fieldNumber}, sfv);
Object value = sfv.fetchObjectField(fieldNumber);
return value;
}
}