Hibernate example source code file (BatchFetchTest.java)

This example Hibernate source code file (BatchFetchTest.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, hibernate, hibernate, holden, iterator, jboss, jboss, model, model, monaro, oss, productline, productline, string, util

The Hibernate BatchFetchTest.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2006-2011, 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.test.batchfetch;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.hibernate.Hibernate;
import org.hibernate.Session;
import org.hibernate.Transaction;

import org.junit.Test;

import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;

/**
 * @author Gavin King
 */
public class BatchFetchTest extends BaseCoreFunctionalTestCase {
	@Override
	public String[] getMappings() {
		return new String[] { "batchfetch/ProductLine.hbm.xml" };
	}

	@SuppressWarnings( {"unchecked"})
	@Test
	public void testBatchFetch() {
		Session s = openSession();
		Transaction t = s.beginTransaction();
		ProductLine cars = new ProductLine();
		cars.setDescription( "Cars" );
		Model monaro = new Model( cars );
		monaro.setName( "monaro" );
		monaro.setDescription( "Holden Monaro" );
		Model hsv = new Model( cars );
		hsv.setName( "hsv" );
		hsv.setDescription( "Holden Commodore HSV" );
		s.save( cars );

		ProductLine oss = new ProductLine();
		oss.setDescription( "OSS" );
		Model jboss = new Model( oss );
		jboss.setName( "JBoss" );
		jboss.setDescription( "JBoss Application Server" );
		Model hibernate = new Model( oss );
		hibernate.setName( "Hibernate" );
		hibernate.setDescription( "Hibernate" );
		Model cache = new Model( oss );
		cache.setName( "JBossCache" );
		cache.setDescription( "JBoss TreeCache" );
		s.save( oss );

		t.commit();
		s.close();

		s.getSessionFactory().getCache().evictEntityRegion( Model.class );
		s.getSessionFactory().getCache().evictEntityRegion( ProductLine.class );

		s = openSession();
		t = s.beginTransaction();

		List list = s.createQuery( "from ProductLine pl order by pl.description" ).list();
		cars = ( ProductLine ) list.get( 0 );
		oss = ( ProductLine ) list.get( 1 );
		assertFalse( Hibernate.isInitialized( cars.getModels() ) );
		assertFalse( Hibernate.isInitialized( oss.getModels() ) );
		assertEquals( cars.getModels().size(), 2 ); //fetch both collections
		assertTrue( Hibernate.isInitialized( cars.getModels() ) );
		assertTrue( Hibernate.isInitialized( oss.getModels() ) );

		s.clear();

		list = s.createQuery( "from Model m" ).list();
		hibernate = ( Model ) s.get( Model.class, hibernate.getId() );
		hibernate.getProductLine().getId();
		for ( Object aList : list ) {
			assertFalse( Hibernate.isInitialized( ((Model) aList).getProductLine() ) );
		}
		assertEquals( hibernate.getProductLine().getDescription(), "OSS" ); //fetch both productlines

		s.clear();

		Iterator iter = s.createQuery( "from Model" ).iterate();
		list = new ArrayList();
		while ( iter.hasNext() ) {
			list.add( iter.next() );
		}
		Model m = ( Model ) list.get( 0 );
		m.getDescription(); //fetch a batch of 4

		s.clear();

		list = s.createQuery( "from ProductLine" ).list();
		ProductLine pl = ( ProductLine ) list.get( 0 );
		ProductLine pl2 = ( ProductLine ) list.get( 1 );
		s.evict( pl2 );
		pl.getModels().size(); //fetch just one collection! (how can we write an assertion for that??)

		t.commit();
		s.close();

		s = openSession();
		t = s.beginTransaction();
		list = s.createQuery( "from ProductLine pl order by pl.description" ).list();
		cars = ( ProductLine ) list.get( 0 );
		oss = ( ProductLine ) list.get( 1 );
		assertEquals( cars.getModels().size(), 2 );
		assertEquals( oss.getModels().size(), 3 );
		s.delete( cars );
		s.delete( oss );
		t.commit();
		s.close();
	}

}