org.hibernate.envers.internal.entities.mapper.relation.lazy.initializor.BasicCollectionInitializor Maven / Gradle / Ivy

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or .
 */
package org.hibernate.envers.internal.entities.mapper.relation.lazy.initializor;

import java.lang.reflect.InvocationTargetException;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Collection;
import java.util.List;
import java.util.Map;

import org.hibernate.envers.boot.internal.EnversService;
import org.hibernate.envers.exception.AuditException;
import org.hibernate.envers.internal.entities.mapper.relation.MiddleComponentData;
import org.hibernate.envers.internal.entities.mapper.relation.query.RelationQueryGenerator;
import org.hibernate.envers.internal.reader.AuditReaderImplementor;
import org.hibernate.internal.util.ReflectHelper;

/**
 * Initializes a non-indexed java collection (set or list, eventually sorted).
 *
 * @author Adam Warski (adam at warski dot org)
 */
public class BasicCollectionInitializor extends AbstractCollectionInitializor {
	protected final Class collectionClass;
	private final MiddleComponentData elementComponentData;

	public BasicCollectionInitializor(
			EnversService enversService,
			AuditReaderImplementor versionsReader,
			RelationQueryGenerator queryGenerator,
			Object primaryKey, Number revision, boolean removed,
			Class collectionClass,
			MiddleComponentData elementComponentData) {
		super( enversService, versionsReader, queryGenerator, primaryKey, revision, removed );

		this.collectionClass = collectionClass;
		this.elementComponentData = elementComponentData;
	}

	@Override
	@SuppressWarnings("unchecked")
	protected T initializeCollection(int size) {
		return AccessController.doPrivileged(
				new PrivilegedAction() {
					@Override
					public T run() {
						try {
							return (T) ReflectHelper.getDefaultConstructor( collectionClass ).newInstance();
						}
						catch (InstantiationException e) {
							throw new AuditException( e );
						}
						catch (IllegalAccessException e) {
							throw new AuditException( e );
						}
						catch (InvocationTargetException e) {
							throw new AuditException( e );
						}
					}
				}
		);
	}

	@Override
	@SuppressWarnings({"unchecked"})
	protected void addToCollection(T collection, Object collectionRow) {
		// collectionRow will be the actual object if retrieved from audit relation or middle table
		// otherwise it will be a List
		Object elementData = collectionRow;
		if ( collectionRow instanceof java.util.List ) {
			elementData = ( (List) collectionRow ).get( elementComponentData.getComponentIndex() );
		}

		// If the target entity is not audited, the elements may be the entities already, so we have to check
		// if they are maps or not.
		Object element;
		if ( elementData instanceof Map ) {
			element = elementComponentData.getComponentMapper().mapToObjectFromFullMap(
					entityInstantiator,
					(Map) elementData, null, revision
			);
		}
		else {
			element = elementData;
		}
		collection.add( element );
	}
}