Hibernate example source code file (BasicCollectionPersister.java)

This example Hibernate source code file (BasicCollectionPersister.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

associationtype, basiccollectionpersister, delete, delete, io, jdbc, joinable, mappingexception, override, override, sessionimplementor, sql, sqlexception, string, string, update, update, util

The Hibernate BasicCollectionPersister.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008, Red Hat Middleware LLC 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 Middleware LLC.
 *
 * 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.persister.collection;
import java.io.Serializable;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Iterator;
import org.hibernate.HibernateException;
import org.hibernate.MappingException;
import org.hibernate.cache.CacheException;
import org.hibernate.cache.spi.access.CollectionRegionAccessStrategy;
import org.hibernate.cfg.Configuration;
import org.hibernate.collection.spi.PersistentCollection;
import org.hibernate.engine.spi.LoadQueryInfluencers;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.engine.spi.SubselectFetch;
import org.hibernate.engine.jdbc.batch.internal.BasicBatchKey;
import org.hibernate.internal.util.collections.ArrayHelper;
import org.hibernate.jdbc.Expectation;
import org.hibernate.jdbc.Expectations;
import org.hibernate.loader.collection.BatchingCollectionInitializer;
import org.hibernate.loader.collection.CollectionInitializer;
import org.hibernate.loader.collection.SubselectCollectionLoader;
import org.hibernate.mapping.Collection;
import org.hibernate.persister.entity.Joinable;
import org.hibernate.pretty.MessageHelper;
import org.hibernate.sql.Delete;
import org.hibernate.sql.Insert;
import org.hibernate.sql.SelectFragment;
import org.hibernate.sql.Update;
import org.hibernate.type.AssociationType;

/**
 * Collection persister for collections of values and many-to-many associations.
 *
 * @author Gavin King
 */
public class BasicCollectionPersister extends AbstractCollectionPersister {

	public boolean isCascadeDeleteEnabled() {
		return false;
	}

	public BasicCollectionPersister(
			Collection collection,
			CollectionRegionAccessStrategy cacheAccessStrategy,
			Configuration cfg,
			SessionFactoryImplementor factory) throws MappingException, CacheException {
		super( collection, cacheAccessStrategy, cfg, factory );
	}

	/**
	 * Generate the SQL DELETE that deletes all rows
	 */
	@Override
    protected String generateDeleteString() {
		
		Delete delete = new Delete()
				.setTableName( qualifiedTableName )
				.addPrimaryKeyColumns( keyColumnNames );
		
		if ( hasWhere ) delete.setWhere( sqlWhereString );
		
		if ( getFactory().getSettings().isCommentsEnabled() ) {
			delete.setComment( "delete collection " + getRole() );
		}
		
		return delete.toStatementString();
	}

	/**
	 * Generate the SQL INSERT that creates a new row
	 */
	@Override
    protected String generateInsertRowString() {
		
		Insert insert = new Insert( getDialect() )
				.setTableName( qualifiedTableName )
				.addColumns( keyColumnNames );
		
		if ( hasIdentifier) insert.addColumn( identifierColumnName );
		
		if ( hasIndex /*&& !indexIsFormula*/ ) {
			insert.addColumns( indexColumnNames, indexColumnIsSettable );
		}
		
		if ( getFactory().getSettings().isCommentsEnabled() ) {
			insert.setComment( "insert collection row " + getRole() );
		}
		
		//if ( !elementIsFormula ) {
			insert.addColumns( elementColumnNames, elementColumnIsSettable, elementColumnWriters );
		//}
		
		return insert.toStatementString();
	}

	/**
	 * Generate the SQL UPDATE that updates a row
	 */
	@Override
    protected String generateUpdateRowString() {
		
		Update update = new Update( getDialect() )
			.setTableName( qualifiedTableName );
		
		//if ( !elementIsFormula ) {
			update.addColumns( elementColumnNames, elementColumnIsSettable, elementColumnWriters );
		//}
		
		if ( hasIdentifier ) {
			update.addPrimaryKeyColumns( new String[]{ identifierColumnName } );
		}
		else if ( hasIndex && !indexContainsFormula ) {
			update.addPrimaryKeyColumns( ArrayHelper.join( keyColumnNames, indexColumnNames ) );
		}
		else {
			update.addPrimaryKeyColumns( keyColumnNames );
			update.addPrimaryKeyColumns( elementColumnNames, elementColumnIsInPrimaryKey, elementColumnWriters );
		}
		
		if ( getFactory().getSettings().isCommentsEnabled() ) {
			update.setComment( "update collection row " + getRole() );
		}
		
		return update.toStatementString();
	}

	/**
	 * Generate the SQL DELETE that deletes a particular row
	 */
	@Override
    protected String generateDeleteRowString() {
		
		Delete delete = new Delete()
			.setTableName( qualifiedTableName );
		
		if ( hasIdentifier ) {
			delete.addPrimaryKeyColumns( new String[]{ identifierColumnName } );
		}
		else if ( hasIndex && !indexContainsFormula ) {
			delete.addPrimaryKeyColumns( ArrayHelper.join( keyColumnNames, indexColumnNames ) );
		}
		else {
			delete.addPrimaryKeyColumns( keyColumnNames );
			delete.addPrimaryKeyColumns( elementColumnNames, elementColumnIsInPrimaryKey, elementColumnWriters );
		}
		
		if ( getFactory().getSettings().isCommentsEnabled() ) {
			delete.setComment( "delete collection row " + getRole() );
		}
		
		return delete.toStatementString();
	}

	public boolean consumesEntityAlias() {
		return false;
	}

	public boolean consumesCollectionAlias() {
//		return !isOneToMany();
		return true;
	}

	public boolean isOneToMany() {
		return false;
	}

	@Override
    public boolean isManyToMany() {
		return elementType.isEntityType(); //instanceof AssociationType;
	}

	private BasicBatchKey updateBatchKey;

	@Override
    protected int doUpdateRows(Serializable id, PersistentCollection collection, SessionImplementor session)
			throws HibernateException {
		
		if ( ArrayHelper.isAllFalse(elementColumnIsSettable) ) return 0;

		try {
			PreparedStatement st = null;
			Expectation expectation = Expectations.appropriateExpectation( getUpdateCheckStyle() );
			boolean callable = isUpdateCallable();
			boolean useBatch = expectation.canBeBatched();
			Iterator entries = collection.entries( this );
			String sql = getSQLUpdateRowString();
			int i = 0;
			int count = 0;
			while ( entries.hasNext() ) {
				Object entry = entries.next();
				if ( collection.needsUpdating( entry, i, elementType ) ) {
					int offset = 1;

					if ( useBatch ) {
						if ( updateBatchKey == null ) {
							updateBatchKey = new BasicBatchKey(
									getRole() + "#UPDATE",
									expectation
							);
						}
						st = session.getTransactionCoordinator()
								.getJdbcCoordinator()
								.getBatch( updateBatchKey )
								.getBatchStatement( sql, callable );
					}
					else {
						st = session.getTransactionCoordinator()
								.getJdbcCoordinator()
								.getStatementPreparer()
								.prepareStatement( sql, callable );
					}

					try {
						offset+= expectation.prepare( st );
						int loc = writeElement( st, collection.getElement( entry ), offset, session );
						if ( hasIdentifier ) {
							writeIdentifier( st, collection.getIdentifier( entry, i ), loc, session );
						}
						else {
							loc = writeKey( st, id, loc, session );
							if ( hasIndex && !indexContainsFormula ) {
								writeIndexToWhere( st, collection.getIndex( entry, i, this ), loc, session );
							}
							else {
								writeElementToWhere( st, collection.getSnapshotElement( entry, i ), loc, session );
							}
						}

						if ( useBatch ) {
							session.getTransactionCoordinator()
									.getJdbcCoordinator()
									.getBatch( updateBatchKey )
									.addToBatch();
						}
						else {
							expectation.verifyOutcome( st.executeUpdate(), st, -1 );
						}
					}
					catch ( SQLException sqle ) {
						if ( useBatch ) {
							session.getTransactionCoordinator().getJdbcCoordinator().abortBatch();
						}
						throw sqle;
					}
					finally {
						if ( !useBatch ) {
							st.close();
						}
					}
					count++;
				}
				i++;
			}
			return count;
		}
		catch ( SQLException sqle ) {
			throw getSQLExceptionHelper().convert(
					sqle,
					"could not update collection rows: " + MessageHelper.collectionInfoString( this, id, getFactory() ),
					getSQLUpdateRowString()
				);
		}
	}

	public String selectFragment(
	        Joinable rhs,
	        String rhsAlias,
	        String lhsAlias,
	        String entitySuffix,
	        String collectionSuffix,
	        boolean includeCollectionColumns) {
		// we need to determine the best way to know that two joinables
		// represent a single many-to-many...
		if ( rhs != null && isManyToMany() && !rhs.isCollection() ) {
			AssociationType elementType = ( ( AssociationType ) getElementType() );
			if ( rhs.equals( elementType.getAssociatedJoinable( getFactory() ) ) ) {
				return manyToManySelectFragment( rhs, rhsAlias, lhsAlias, collectionSuffix );
			}
		}
		return includeCollectionColumns ? selectFragment( lhsAlias, collectionSuffix ) : "";
	}

	private String manyToManySelectFragment(
	        Joinable rhs,
	        String rhsAlias,
	        String lhsAlias,
	        String collectionSuffix) {
		SelectFragment frag = generateSelectFragment( lhsAlias, collectionSuffix );

		String[] elementColumnNames = rhs.getKeyColumnNames();
		frag.addColumns( rhsAlias, elementColumnNames, elementColumnAliases );
		appendIndexColumns( frag, lhsAlias );
		appendIdentifierColumns( frag, lhsAlias );

		return frag.toFragmentString()
				.substring( 2 ); //strip leading ','
	}

	/**
	 * Create the <tt>CollectionLoader
	 *
	 * @see org.hibernate.loader.collection.BasicCollectionLoader
	 */
	@Override
    protected CollectionInitializer createCollectionInitializer(LoadQueryInfluencers loadQueryInfluencers)
			throws MappingException {
		return BatchingCollectionInitializer.createBatchingCollectionInitializer( this, batchSize, getFactory(), loadQueryInfluencers );
	}

	public String fromJoinFragment(String alias, boolean innerJoin, boolean includeSubclasses) {
		return "";
	}

	public String whereJoinFragment(String alias, boolean innerJoin, boolean includeSubclasses) {
		return "";
	}

	@Override
    protected CollectionInitializer createSubselectInitializer(SubselectFetch subselect, SessionImplementor session) {
		return new SubselectCollectionLoader( 
				this,
				subselect.toSubselectString( getCollectionType().getLHSPropertyName() ),
				subselect.getResult(),
				subselect.getQueryParameters(),
				subselect.getNamedParameterLocMap(),
				session.getFactory(),
				session.getLoadQueryInfluencers() 
		);
	}

}