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Hibernate example source code file (BatchedManyToManyTest.java)

This example Hibernate source code file (BatchedManyToManyTest.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

abstractcollectionpersister, collectionstatistics, group, group, list, override, override, session, string, string, test, testingbatch, user, user, util

The Hibernate BatchedManyToManyTest.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2009-2011, 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.manytomany.batchload;

import java.util.List;

import org.hibernate.EmptyInterceptor;
import org.hibernate.Hibernate;
import org.hibernate.Interceptor;
import org.hibernate.Session;
import org.hibernate.cfg.Configuration;
import org.hibernate.cfg.Environment;
import org.hibernate.engine.jdbc.batch.internal.BatchBuilderImpl;
import org.hibernate.engine.jdbc.batch.internal.NonBatchingBatch;
import org.hibernate.engine.jdbc.batch.spi.Batch;
import org.hibernate.engine.jdbc.batch.spi.BatchKey;
import org.hibernate.engine.jdbc.spi.JdbcCoordinator;
import org.hibernate.loader.collection.BatchingCollectionInitializer;
import org.hibernate.persister.collection.AbstractCollectionPersister;
import org.hibernate.stat.CollectionStatistics;

import org.junit.Test;
import junit.framework.Assert;

import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;

import static org.hibernate.testing.junit4.ExtraAssertions.assertClassAssignability;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

/**
 * Tests loading of many-to-many collection which should trigger
 * a batch load.
 *
 * @author Steve Ebersole
 */
public class BatchedManyToManyTest extends BaseCoreFunctionalTestCase {
	@Override
	public String[] getMappings() {
		return new String[] { "manytomany/batchload/UserGroupBatchLoad.hbm.xml" };
	}

	@Override
	public void configure(Configuration cfg) {
		cfg.setProperty( Environment.USE_SECOND_LEVEL_CACHE, "false" );
		cfg.setProperty( Environment.GENERATE_STATISTICS, "true" );
		cfg.setProperty( Environment.BATCH_STRATEGY, TestingBatchBuilder.class.getName() );
	}

	public static class TestingBatchBuilder extends BatchBuilderImpl {
		@Override
		public Batch buildBatch(BatchKey key, JdbcCoordinator jdbcCoordinator) {
			return new TestingBatch( key, jdbcCoordinator );
		}
	}

	public static class TestingBatch extends NonBatchingBatch {
		public TestingBatch(BatchKey key, JdbcCoordinator jdbcCoordinator) {
			super( key, jdbcCoordinator );
		}
	}

	@Test
	public void testProperLoaderSetup() {
		AbstractCollectionPersister cp = ( AbstractCollectionPersister )
				sessionFactory().getCollectionPersister( User.class.getName() + ".groups" );
		assertClassAssignability( BatchingCollectionInitializer.class, cp.getInitializer().getClass() );
		BatchingCollectionInitializer initializer = ( BatchingCollectionInitializer ) cp.getInitializer();
		assertEquals( 50, findMaxBatchSize( initializer.getBatchSizes() ) );
	}

	private int findMaxBatchSize(int[] batchSizes) {
		int max = 0;
		for ( int size : batchSizes ) {
			if ( size > max ) {
				max = size;
			}
		}
		return max;
	}

	@Test
	public void testLoadingNonInverseSide() {
		prepareTestData();

		sessionFactory().getStatistics().clear();
		CollectionStatistics userGroupStats = sessionFactory().getStatistics()
				.getCollectionStatistics( User.class.getName() + ".groups" );
		CollectionStatistics groupUserStats = sessionFactory().getStatistics()
				.getCollectionStatistics( Group.class.getName() + ".users" );

		Interceptor testingInterceptor = new EmptyInterceptor() {
			@Override
            public String onPrepareStatement(String sql) {
				// ugh, this is the best way I could come up with to assert this.
				// unfortunately, this is highly dependent on the dialect and its
				// outer join fragment.  But at least this wil fail on the majority
				// of dialects...
				Assert.assertFalse(
						"batch load of many-to-many should use inner join",
						sql.toLowerCase().contains( "left outer join" )
				);
				return super.onPrepareStatement( sql );
			}
		};

		Session s = openSession( testingInterceptor );
		s.beginTransaction();
		List users = s.createQuery( "from User u" ).list();
		User user = ( User ) users.get( 0 );
		assertTrue( Hibernate.isInitialized( user ) );
		assertTrue( Hibernate.isInitialized( user.getGroups() ) );
		user = ( User ) users.get( 1 );
		assertTrue( Hibernate.isInitialized( user ) );
		assertTrue( Hibernate.isInitialized( user.getGroups() ) );
		assertEquals( 1, userGroupStats.getFetchCount() ); // should have been just one fetch (the batch fetch)
		assertEquals( 1, groupUserStats.getFetchCount() ); // should have been just one fetch (the batch fetch)
		s.getTransaction().commit();
		s.close();

		cleanupTestData();
	}

	protected void prepareTestData() {
		// set up the test data
		User me = new User( "steve" );
		User you = new User( "not steve" );
		Group developers = new Group( "developers" );
		Group translators = new Group( "translators" );
		Group contributors = new Group( "contributors" );
		me.getGroups().add( developers );
		developers.getUsers().add( me );
		you.getGroups().add( translators );
		translators.getUsers().add( you );
		you.getGroups().add( contributors );
		contributors.getUsers().add( you );
		Session s = openSession();
		s.beginTransaction();
		s.save( me );
		s.save( you );
		s.getTransaction().commit();
		s.close();
	}

	protected void cleanupTestData() {
		// clean up the test data
		Session s = openSession();
		s.beginTransaction();
		// User is the non-inverse side...
		List<User> users = s.createQuery( "from User" ).list();
		for ( User user : users ) {
			s.delete( user );
		}
		s.flush();
		s.createQuery( "delete Group" ).executeUpdate();
		s.getTransaction().commit();
		s.close();
	}
}

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