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Hibernate example source code file (PersistentElementHolder.java)

This example Hibernate source code file (PersistentElementHolder.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Hibernate tags/keywords

arraylist, arraylist, collectionpersister, element, element, hibernateexception, hibernateexception, io, jdbc, list, object, object, override, persistentelementholder, serializable, sql, type, util

The Hibernate PersistentElementHolder.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008-2011, Red Hat Inc. or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.collection.internal;

import java.io.Serializable;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

import org.dom4j.Element;

import org.hibernate.AssertionFailure;
import org.hibernate.HibernateException;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.internal.util.collections.CollectionHelper;
import org.hibernate.loader.CollectionAliases;
import org.hibernate.persister.collection.CollectionPersister;
import org.hibernate.type.Type;

/**
 * A persistent wrapper for an XML element
 *
 * @author Gavin King
 */
public class PersistentElementHolder extends AbstractPersistentCollection {
	protected Element element;

	public PersistentElementHolder(SessionImplementor session, Element element) {
		super(session);
		this.element = element;
		setInitialized();
	}

	public Serializable getSnapshot(CollectionPersister persister)
	throws HibernateException {

		final Type elementType = persister.getElementType();
		List elements = element.elements( persister.getElementNodeName() );
		ArrayList snapshot = new ArrayList( elements.size() );
		for ( int i=0; i<elements.size(); i++ ) {
			Element elem = (Element) elements.get(i);
			Object value = elementType.fromXMLNode( elem, persister.getFactory() );
			Object copy = elementType.deepCopy(value , persister.getFactory() );
			snapshot.add(copy);
		}
		return snapshot;

	}

	@Override
    public Collection getOrphans(Serializable snapshot, String entityName)
	throws HibernateException {
		//orphan delete not supported for EntityMode.DOM4J
		return CollectionHelper.EMPTY_COLLECTION;
	}

	public PersistentElementHolder(SessionImplementor session, CollectionPersister persister, Serializable key)
	throws HibernateException {
		super(session);
		Element owner = (Element) session.getPersistenceContext().getCollectionOwner(key, persister);
		if (owner==null) throw new AssertionFailure("null owner");
		//element = XMLHelper.generateDom4jElement( persister.getNodeName() );
		final String nodeName = persister.getNodeName();
		if ( ".".equals(nodeName) ) {
			element = owner;
		}
		else {
			element = owner.element( nodeName );
			if (element==null) element = owner.addElement( nodeName );
		}
	}

	public boolean isWrapper(Object collection) {
		return element==collection;
	}

	public boolean equalsSnapshot(CollectionPersister persister) throws HibernateException {
		Type elementType = persister.getElementType();

		ArrayList snapshot = (ArrayList) getSnapshot();
		List elements = element.elements( persister.getElementNodeName() );
		if ( snapshot.size()!= elements.size() ) return false;
		for ( int i=0; i<snapshot.size(); i++ ) {
			Object old = snapshot.get(i);
			Element elem = (Element) elements.get(i);
			Object current = elementType.fromXMLNode( elem, persister.getFactory() );
			if ( elementType.isDirty( old, current, getSession() ) ) return false;
		}
		return true;
	}

	public boolean isSnapshotEmpty(Serializable snapshot) {
		return ( (Collection) snapshot ).isEmpty();
	}

	@Override
    public boolean empty() {
		return !element.elementIterator().hasNext();
	}

	public Object readFrom(ResultSet rs, CollectionPersister persister, CollectionAliases descriptor, Object owner)
	throws HibernateException, SQLException {
		Object object = persister.readElement( rs, owner, descriptor.getSuffixedElementAliases(), getSession() );
		final Type elementType = persister.getElementType();
		Element subelement = element.addElement( persister.getElementNodeName() );
		elementType.setToXMLNode( subelement, object, persister.getFactory() );
		return object;
	}

	public Iterator entries(CollectionPersister persister) {

		final Type elementType = persister.getElementType();
		List elements =  element.elements( persister.getElementNodeName() );
		int length = elements.size();
		List result = new ArrayList(length);
		for ( int i=0; i<length; i++ ) {
			Element elem = (Element) elements.get(i);
			Object object = elementType.fromXMLNode( elem, persister.getFactory() );
			result.add(object);
		}
		return result.iterator();
	}

	public void beforeInitialize(CollectionPersister persister, int anticipatedSize) {}

	@Override
    public boolean isDirectlyAccessible() {
		return true;
	}

	public void initializeFromCache(CollectionPersister persister, Serializable disassembled, Object owner)
	throws HibernateException {

		Type elementType = persister.getElementType();
		Serializable[] cached = (Serializable[]) disassembled;
		for ( int i=0; i<cached.length; i++ ) {
			Object object = elementType.assemble( cached[i], getSession(), owner );
			Element subelement = element.addElement( persister.getElementNodeName() );
			elementType.setToXMLNode( subelement, object, persister.getFactory() );
		}

	}

	public Serializable disassemble(CollectionPersister persister) throws HibernateException {

		Type elementType = persister.getElementType();
		List elements =  element.elements( persister.getElementNodeName() );
		int length = elements.size();
		Serializable[] result = new Serializable[length];
		for ( int i=0; i<length; i++ ) {
			Element elem = (Element) elements.get(i);
			Object object = elementType.fromXMLNode( elem, persister.getFactory() );
			result[i] = elementType.disassemble( object, getSession(), null );
		}
		return result;
	}

	@Override
    public Object getValue() {
		return element;
	}

	public Iterator getDeletes(CollectionPersister persister, boolean indexIsFormula)
	throws HibernateException {

		Type elementType = persister.getElementType();
		ArrayList snapshot = (ArrayList) getSnapshot();
		List elements = element.elements( persister.getElementNodeName() );
		ArrayList result = new ArrayList();
		for ( int i=0; i<snapshot.size(); i++ ) {
			Object old = snapshot.get(i);
			if ( i >= elements.size() ) {
				result.add(old);
			}
			else {
				Element elem = (Element) elements.get(i);
				Object object = elementType.fromXMLNode( elem, persister.getFactory() );
				if ( elementType.isDirty( old, object, getSession() ) ) result.add(old);
			}
		}
		return result.iterator();

	}

	public boolean needsInserting(Object entry, int i, Type elementType)
	throws HibernateException {
		ArrayList snapshot = (ArrayList) getSnapshot();
		return i>=snapshot.size() || elementType.isDirty( snapshot.get(i), entry, getSession() );
	}

	public boolean needsUpdating(Object entry, int i, Type elementType)
	throws HibernateException {
		return false;
	}

	public Object getIndex(Object entry, int i, CollectionPersister persister) {
		throw new UnsupportedOperationException();
	}

	public Object getElement(Object entry) {
		return entry;
	}

	public Object getSnapshotElement(Object entry, int i) {
		throw new UnsupportedOperationException();
	}

	public boolean entryExists(Object entry, int i) {
		return entry!=null;
	}

}

Other Hibernate examples (source code examples)

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