cascadeentityjoinwalker.java

一个Java持久层类库

//$Id: CascadeEntityJoinWalker.java 9889 2006-05-05 01:24:12Z [e-mail] $
package org.hibernate.loader.entity;

import org.hibernate.FetchMode;
import org.hibernate.LockMode;
import org.hibernate.MappingException;
import org.hibernate.engine.CascadeStyle;
import org.hibernate.engine.CascadingAction;
import org.hibernate.engine.SessionFactoryImplementor;
import org.hibernate.loader.AbstractEntityJoinWalker;
import org.hibernate.persister.entity.OuterJoinLoadable;
import org.hibernate.type.AssociationType;
import org.hibernate.util.CollectionHelper;

public class CascadeEntityJoinWalker extends AbstractEntityJoinWalker {
	
	private final CascadingAction cascadeAction;

	public CascadeEntityJoinWalker(OuterJoinLoadable persister, CascadingAction action, SessionFactoryImplementor factory) 
	throws MappingException {
		super( persister, factory, CollectionHelper.EMPTY_MAP );
		this.cascadeAction = action;
		StringBuffer whereCondition = whereString( getAlias(), persister.getIdentifierColumnNames(), 1 )
				//include the discriminator and class-level where, but not filters
				.append( persister.filterFragment( getAlias(), CollectionHelper.EMPTY_MAP ) );
	
		initAll( whereCondition.toString(), "", LockMode.READ );
	}

	protected boolean isJoinedFetchEnabled(AssociationType type, FetchMode config, CascadeStyle cascadeStyle) {
		return ( type.isEntityType() || type.isCollectionType() ) &&
				( cascadeStyle==null || cascadeStyle.doCascade(cascadeAction) );
	}

	protected boolean isTooManyCollections() {
		return countCollectionPersisters(associations)>0;
	}

	public String getComment() {
		return "load " + getPersister().getEntityName();
	}
	
}