customloader.java

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//$Id: CustomLoader.java 10087 2006-07-06 12:21:30Z [e-mail] $
package org.hibernate.loader.custom;

import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.HashSet;

import org.hibernate.HibernateException;
import org.hibernate.LockMode;
import org.hibernate.QueryException;
import org.hibernate.ScrollableResults;
import org.hibernate.engine.QueryParameters;
import org.hibernate.engine.SessionFactoryImplementor;
import org.hibernate.engine.SessionImplementor;
import org.hibernate.hql.HolderInstantiator;
import org.hibernate.loader.CollectionAliases;
import org.hibernate.loader.EntityAliases;
import org.hibernate.loader.Loader;
import org.hibernate.persister.collection.CollectionPersister;
import org.hibernate.persister.collection.QueryableCollection;
import org.hibernate.persister.entity.Loadable;
import org.hibernate.persister.entity.Queryable;
import org.hibernate.transform.ResultTransformer;
import org.hibernate.type.Type;
import org.hibernate.type.TypeFactory;
import org.hibernate.type.EntityType;
import org.hibernate.type.CollectionType;
import org.hibernate.util.ArrayHelper;

/**
 * Extension point for loaders which use a SQL result set with "unexpected" column aliases.
 * 
 * @author Gavin King
 * @author Steve Ebersole
 */
public class CustomLoader extends Loader {
	
	// Currently *not* cachable if autodiscover types is in effect (e.g. "select * ...")

	private final String sql;
	private final Set querySpaces = new HashSet();
	private final Map namedParameterBindPoints;

	private final Queryable[] entityPersisters;
	private final int[] entiytOwners;
	private final EntityAliases[] entityAliases;

	private final QueryableCollection[] collectionPersisters;
	private final int[] collectionOwners;
	private final CollectionAliases[] collectionAliases;

	private final LockMode[] lockModes;
//	private final String[] sqlAliases;
//	private final String[] sqlAliasSuffixes;
	private final ResultRowProcessor rowProcessor;

	// this is only needed (afaict) for processing results from the query cache;
	// however, this cannot possibly work in the case of discovered types...
	private Type[] resultTypes;

	// this is only needed (afaict) for ResultTransformer processing...
	private String[] transformerAliases;


	public CustomLoader(CustomQuery customQuery, SessionFactoryImplementor factory) {
		super( factory );

		this.sql = customQuery.getSQL();
		this.querySpaces.addAll( customQuery.getQuerySpaces() );
		this.namedParameterBindPoints = customQuery.getNamedParameterBindPoints();

		List entityPersisters = new ArrayList();
		List entityOwners = new ArrayList();
		List entityAliases = new ArrayList();

		List collectionPersisters = new ArrayList();
		List collectionOwners = new ArrayList();
		List collectionAliases = new ArrayList();

		List lockModes = new ArrayList();
		List resultColumnProcessors = new ArrayList();
		List nonScalarReturnList = new ArrayList();
		List resultTypes = new ArrayList();
		List specifiedAliases = new ArrayList();
		int returnableCounter = 0;
		boolean hasScalars = false;

		Iterator itr = customQuery.getCustomQueryReturns().iterator();
		while ( itr.hasNext() ) {
			final Return rtn = ( Return ) itr.next();
			if ( rtn instanceof ScalarReturn ) {
				ScalarReturn scalarRtn = ( ScalarReturn ) rtn;
				resultTypes.add( scalarRtn.getType() );
				specifiedAliases.add( scalarRtn.getColumnAlias() );
				resultColumnProcessors.add(
						new ScalarResultColumnProcessor(
								scalarRtn.getColumnAlias(),
								scalarRtn.getType()
						)
				);
				hasScalars = true;
			}
			else if ( rtn instanceof RootReturn ) {
				RootReturn rootRtn = ( RootReturn ) rtn;
				Queryable persister = ( Queryable ) factory.getEntityPersister( rootRtn.getEntityName() );
				entityPersisters.add( persister );
				lockModes.add( rootRtn.getLockMode() );
				resultColumnProcessors.add( new NonScalarResultColumnProcessor( returnableCounter++ ) );
				nonScalarReturnList.add( rtn );
				entityOwners.add( new Integer( -1 ) );
				resultTypes.add( persister.getType() );
				specifiedAliases.add( rootRtn.getAlias() );
				entityAliases.add( rootRtn.getEntityAliases() );
				ArrayHelper.addAll( querySpaces, persister.getQuerySpaces() );
			}
			else if ( rtn instanceof CollectionReturn ) {
				CollectionReturn collRtn = ( CollectionReturn ) rtn;
				String role = collRtn.getOwnerEntityName() + "." + collRtn.getOwnerProperty();
				QueryableCollection persister = ( QueryableCollection ) factory.getCollectionPersister( role );
				collectionPersisters.add( persister );
				lockModes.add( collRtn.getLockMode() );
				resultColumnProcessors.add( new NonScalarResultColumnProcessor( returnableCounter++ ) );
				nonScalarReturnList.add( rtn );
				collectionOwners.add( new Integer( -1 ) );
				resultTypes.add( persister.getType() );
				specifiedAliases.add( collRtn.getAlias() );
				collectionAliases.add( collRtn.getCollectionAliases() );
				// determine if the collection elements are entities...
				Type elementType = persister.getElementType();
				if ( elementType.isEntityType() ) {
					Queryable elementPersister = ( Queryable ) ( ( EntityType ) elementType ).getAssociatedJoinable( factory );
					entityPersisters.add( elementPersister );
					entityOwners.add( new Integer( -1 ) );
					entityAliases.add( collRtn.getElementEntityAliases() );
					ArrayHelper.addAll( querySpaces, elementPersister.getQuerySpaces() );
				}
			}
			else if ( rtn instanceof EntityFetchReturn ) {
				EntityFetchReturn fetchRtn = ( EntityFetchReturn ) rtn;
				NonScalarReturn ownerDescriptor = fetchRtn.getOwner();
				int ownerIndex = nonScalarReturnList.indexOf( ownerDescriptor );
				entityOwners.add( new Integer( ownerIndex ) );
				lockModes.add( fetchRtn.getLockMode() );
				Queryable ownerPersister = determineAppropriateOwnerPersister( ownerDescriptor );
				EntityType fetchedType = ( EntityType ) ownerPersister.getPropertyType( fetchRtn.getOwnerProperty() );
				String entityName = fetchedType.getAssociatedEntityName( getFactory() );
				Queryable persister = ( Queryable ) factory.getEntityPersister( entityName );
				entityPersisters.add( persister );
				nonScalarReturnList.add( rtn );
				specifiedAliases.add( fetchRtn.getAlias() );
				entityAliases.add( fetchRtn.getEntityAliases() );
				ArrayHelper.addAll( querySpaces, persister.getQuerySpaces() );
			}
			else if ( rtn instanceof CollectionFetchReturn ) {
				CollectionFetchReturn fetchRtn = ( CollectionFetchReturn ) rtn;
				NonScalarReturn ownerDescriptor = fetchRtn.getOwner();
				int ownerIndex = nonScalarReturnList.indexOf( ownerDescriptor );
				collectionOwners.add( new Integer( ownerIndex ) );
				lockModes.add( fetchRtn.getLockMode() );
				Queryable ownerPersister = determineAppropriateOwnerPersister( ownerDescriptor );
				String role = ownerPersister.getEntityName() + '.' + fetchRtn.getOwnerProperty();
				QueryableCollection persister = ( QueryableCollection ) factory.getCollectionPersister( role );
				collectionPersisters.add( persister );
				nonScalarReturnList.add( rtn );
				specifiedAliases.add( fetchRtn.getAlias() );
				collectionAliases.add( fetchRtn.getCollectionAliases() );
				// determine if the collection elements are entities...
				Type elementType = persister.getElementType();
				if ( elementType.isEntityType() ) {
					Queryable elementPersister = ( Queryable ) ( ( EntityType ) elementType ).getAssociatedJoinable( factory );
					entityPersisters.add( elementPersister );
					entityOwners.add( new Integer( ownerIndex ) );
					entityAliases.add( fetchRtn.getElementEntityAliases() );
					ArrayHelper.addAll( querySpaces, elementPersister.getQuerySpaces() );
				}
			}
			else {
				throw new HibernateException( "unexpected custom query return type : " + rtn.getClass().getName() );
			}
		}

		this.entityPersisters = new Queryable[ entityPersisters.size() ];
		for ( int i = 0; i < entityPersisters.size(); i++ ) {
			this.entityPersisters[i] = ( Queryable ) entityPersisters.get( i );
		}
		this.entiytOwners = ArrayHelper.toIntArray( entityOwners );
		this.entityAliases = new EntityAliases[ entityAliases.size() ];
		for ( int i = 0; i < entityAliases.size(); i++ ) {
			this.entityAliases[i] = ( EntityAliases ) entityAliases.get( i );
		}

		this.collectionPersisters = new QueryableCollection[ collectionPersisters.size() ];
		for ( int i = 0; i < collectionPersisters.size(); i++ ) {
			this.collectionPersisters[i] = ( QueryableCollection ) collectionPersisters.get( i );
		}
		this.collectionOwners = ArrayHelper.toIntArray( collectionOwners );
		this.collectionAliases = new CollectionAliases[ collectionAliases.size() ];
		for ( int i = 0; i < collectionAliases.size(); i++ ) {
			this.collectionAliases[i] = ( CollectionAliases ) collectionAliases.get( i );
		}

		this.lockModes = new LockMode[ lockModes.size() ];
		for ( int i = 0; i < lockModes.size(); i++ ) {
			this.lockModes[i] = ( LockMode ) lockModes.get( i );
		}

		this.resultTypes = ArrayHelper.toTypeArray( resultTypes );
		this.transformerAliases = ArrayHelper.toStringArray( specifiedAliases );

		this.rowProcessor = new ResultRowProcessor(
				hasScalars,
		        ( ResultColumnProcessor[] ) resultColumnProcessors.toArray( new ResultColumnProcessor[ resultColumnProcessors.size() ] )
		);
	}

	private Queryable determineAppropriateOwnerPersister(NonScalarReturn ownerDescriptor) {
		String entityName = null;
		if ( ownerDescriptor instanceof RootReturn ) {
			entityName = ( ( RootReturn ) ownerDescriptor ).getEntityName();
		}
		else if ( ownerDescriptor instanceof CollectionReturn ) {
			CollectionReturn collRtn = ( CollectionReturn ) ownerDescriptor;
			String role = collRtn.getOwnerEntityName() + "." + collRtn.getOwnerProperty();
			CollectionPersister persister = getFactory().getCollectionPersister( role );
			EntityType ownerType = ( EntityType ) persister.getElementType();
			entityName = ownerType.getAssociatedEntityName( getFactory() );
		}
		else if ( ownerDescriptor instanceof FetchReturn ) {
			FetchReturn fetchRtn = ( FetchReturn ) ownerDescriptor;
			Queryable persister = determineAppropriateOwnerPersister( fetchRtn.getOwner() );
			Type ownerType = persister.getPropertyType( fetchRtn.getOwnerProperty() );
			if ( ownerType.isEntityType() ) {
				entityName = ( ( EntityType ) ownerType ).getAssociatedEntityName( getFactory() );
			}
			else if ( ownerType.isCollectionType() ) {
				Type ownerCollectionElementType = ( ( CollectionType ) ownerType ).getElementType( getFactory() );
				if ( ownerCollectionElementType.isEntityType() ) {
					entityName = ( ( EntityType ) ownerCollectionElementType ).getAssociatedEntityName( getFactory() );
				}
			}
		}

		if ( entityName == null ) {
			throw new HibernateException( "Could not determine fetch owner : " + ownerDescriptor );
		}

		return ( Queryable ) getFactory().getEntityPersister( entityName );
	}

	protected String getQueryIdentifier() {
		return sql;
	}

	protected String getSQLString() {
		return sql;
	}

	public Set getQuerySpaces() {
		return querySpaces;
	}

	protected LockMode[] getLockModes(Map lockModesMap) {
		return lockModes;
	}

	protected Loadable[] getEntityPersisters() {
		return entityPersisters;
	}

	protected CollectionPersister[] getCollectionPersisters() {
		return collectionPersisters;
	}

	protected int[] getCollectionOwners() {
		return collectionOwners;
	}
	
	protected int[] getOwners() {
		return entiytOwners;