scheduledcollectionupdate.java

用Java实现的23个常用设计模式源代码

//$Id: ScheduledCollectionUpdate.java,v 1.9.2.6 2003/11/24 03:25:30 oneovthafew Exp $
package net.sf.hibernate.impl;

import java.io.Serializable;

import net.sf.hibernate.AssertionFailure;
import net.sf.hibernate.HibernateException;
import net.sf.hibernate.collection.CollectionPersister;
import net.sf.hibernate.collection.PersistentCollection;
import net.sf.hibernate.engine.SessionImplementor;

final class ScheduledCollectionUpdate extends ScheduledCollectionAction implements SessionImpl.Executable {
	
	private final PersistentCollection collection;
	private final boolean emptySnapshot;
	
	public ScheduledCollectionUpdate(
		PersistentCollection collection, 
		CollectionPersister persister, 
		Serializable id, 
		boolean emptySnapshot,
		SessionImplementor session) {
		super(persister, id, session);
		this.collection = collection;
		this.emptySnapshot = emptySnapshot;
	}
	
	public void execute() throws HibernateException {
		Serializable id = getId();
		SessionImplementor session = getSession();
		CollectionPersister persister = getPersister();
		
		if ( persister.hasCache() ) setLock( persister.getCache().lock(id) );
		
		if ( !collection.wasInitialized() ) {
			if ( !collection.hasQueuedAdditions() ) throw new AssertionFailure("bug processing queued adds");
			//do nothing - we only need to notify the cache...
		}
		else if ( collection.empty() ) {
			if (!emptySnapshot) persister.remove(id, session);
		}
		else if ( collection.needsRecreate( getPersister() ) ) {
			if (!emptySnapshot) persister.remove(id, session);
			persister.recreate(collection, id, session);
		}
		else {
			persister.deleteRows(collection, id, session);
			persister.updateRows(collection, id, session);
			persister.insertRows(collection, id, session);
		}
		
		if ( persister.hasCache() ) persister.getCache().evict(id);
	}
	
}