/*
 * 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 <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.internal;

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.NoSuchElementException;

import org.hibernate.HibernateException;
import org.hibernate.JDBCException;
import org.hibernate.engine.HibernateIterator;
import org.hibernate.event.spi.EventSource;
import org.hibernate.hql.internal.HolderInstantiator;
import org.hibernate.type.EntityType;
import org.hibernate.type.Type;

An implementation of java.util.Iterator that is returned by iterate() query execution methods.
Author:Gavin King
/** * An implementation of <tt>java.util.Iterator</tt> that is * returned by <tt>iterate()</tt> query execution methods. * * @author Gavin King */
public final class IteratorImpl implements HibernateIterator { private static final CoreMessageLogger LOG = CoreLogging.messageLogger( IteratorImpl.class ); private ResultSet rs; private final EventSource session; private boolean readOnly; private final Type[] types; private final boolean single; private Object currentResult; private boolean hasNext; private final String[][] names; private PreparedStatement ps; private HolderInstantiator holderInstantiator; public IteratorImpl( ResultSet rs, PreparedStatement ps, EventSource sess, boolean readOnly, Type[] types, String[][] columnNames, HolderInstantiator holderInstantiator) throws HibernateException, SQLException { this.rs = rs; this.ps = ps; this.session = sess; this.readOnly = readOnly; this.types = types; this.names = columnNames; this.holderInstantiator = holderInstantiator; single = types.length == 1; postNext(); } public void close() throws JDBCException { if ( ps != null ) { LOG.debug( "Closing iterator" ); session.getJdbcCoordinator().getResourceRegistry().release( ps ); try { session.getPersistenceContext().getLoadContexts().cleanup( rs ); } catch (Throwable ignore) { // ignore this error for now LOG.debugf( "Exception trying to cleanup load context : %s", ignore.getMessage() ); } session.getJdbcCoordinator().afterStatementExecution(); ps = null; rs = null; hasNext = false; } } private void postNext() throws SQLException { LOG.debug( "Attempting to retrieve next results" ); this.hasNext = rs.next(); if ( !hasNext ) { LOG.debug( "Exhausted results" ); close(); } else { LOG.debug( "Retrieved next results" ); } } public boolean hasNext() { return hasNext; } public Object next() throws HibernateException { if ( !hasNext ) { throw new NoSuchElementException( "No more results" ); } boolean sessionDefaultReadOnlyOrig = session.isDefaultReadOnly(); session.setDefaultReadOnly( readOnly ); try { boolean isHolder = holderInstantiator.isRequired(); LOG.debugf( "Assembling results" ); if ( single && !isHolder ) { currentResult = types[0].nullSafeGet( rs, names[0], session, null ); } else { Object[] currentResults = new Object[types.length]; for ( int i = 0; i < types.length; i++ ) { currentResults[i] = types[i].nullSafeGet( rs, names[i], session, null ); } if ( isHolder ) { currentResult = holderInstantiator.instantiate( currentResults ); } else { currentResult = currentResults; } } postNext(); LOG.debugf( "Returning current results" ); return currentResult; } catch (SQLException sqle) { throw session.getFactory().getSQLExceptionHelper().convert( sqle, "could not get next iterator result" ); } finally { session.setDefaultReadOnly( sessionDefaultReadOnlyOrig ); } } public void remove() { if ( !single ) { throw new UnsupportedOperationException( "Not a single column hibernate query result set" ); } if ( currentResult == null ) { throw new IllegalStateException( "Called Iterator.remove() before next()" ); } if ( !( types[0] instanceof EntityType ) ) { throw new UnsupportedOperationException( "Not an entity" ); } session.delete( ( (EntityType) types[0] ).getAssociatedEntityName(), currentResult, false, null ); } }