Hibernate example source code file (ScrollableCollectionFetchingTest.java)

This example Hibernate source code file (ScrollableCollectionFetchingTest.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

animal, animal, hibernateexception, long, scrollablecollectionfetchingtest, scrollableresults, session, session, string, test, testdata, testdata, transaction, transaction

The Hibernate ScrollableCollectionFetchingTest.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.hql;

import org.hibernate.HibernateException;
import org.hibernate.ScrollMode;
import org.hibernate.ScrollableResults;
import org.hibernate.Session;
import org.hibernate.Transaction;

import org.junit.Test;

import org.hibernate.testing.DialectChecks;
import org.hibernate.testing.RequiresDialectFeature;
import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;

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

/**
 * Tests the new functionality of allowing scrolling of results which
 * contain collection fetches.
 *
 * @author Steve Ebersole
 */
public class ScrollableCollectionFetchingTest extends BaseCoreFunctionalTestCase {
	public String[] getMappings() {
		return new String[] { "hql/Animal.hbm.xml" };
	}

	@Test
	public void testTupleReturnFails() {
		Session s = openSession();
		Transaction txn = s.beginTransaction();

		try {
			s.createQuery( "select a, a.weight from Animal a inner join fetch a.offspring" ).scroll();
			fail( "scroll allowed with collection fetch and reurning tuples" );
		}
		catch( HibernateException e ) {
			// expected result...
		}

		txn.commit();
		s.close();
	}

	@Test
	public void testScrollingJoinFetchesEmptyResultSet() {
		Session s = openSession();
		Transaction txn = s.beginTransaction();

		final String query = "from Animal a left join fetch a.offspring where a.description like :desc order by a.id";

		// first, as a control, make sure there are no results
		int size = s.createQuery( query ).setString( "desc", "root%" ).list().size();
		assertEquals( 0, size );

		// now get the scrollable results
		ScrollableResults results = s.createQuery( query ).setString( "desc", "root%" ).scroll();

		assertFalse( results.isFirst() );
		assertFalse( results.isLast() );

		assertFalse( results.next() );
		assertFalse( results.isFirst() );
		assertFalse( results.isLast() );

		assertFalse( results.previous() );
		assertFalse( results.isFirst() );
		assertFalse( results.isLast() );

		results.beforeFirst();
		assertFalse( results.isFirst() );
		assertFalse( results.isLast() );
		assertFalse( results.next() );

		assertFalse( results.first() );
		assertFalse( results.isFirst() );
		assertFalse( results.isLast() );
		assertFalse( results.next() );

		results.afterLast();
		assertFalse( results.isFirst() );
		assertFalse( results.isLast() );
		assertFalse( results.next() );

		assertFalse( results.last() );
		assertFalse( results.isFirst() );
		assertFalse( results.isLast() );
		assertFalse( results.next() );

		for ( int i=1; i<3; i++ ) {
			assertFalse( results.scroll( i ) );
			assertFalse( results.isFirst() );
			assertFalse( results.isLast() );

			assertFalse( results.scroll( - i ) );
			assertFalse( results.isFirst() );
			assertFalse( results.isLast() );

			assertFalse( results.setRowNumber( i ) );
			assertFalse( results.isFirst() );
			assertFalse( results.isLast() );

			assertFalse( results.setRowNumber( - i ) );
			assertFalse( results.isFirst() );
			assertFalse( results.isLast() );
		}

		txn.commit();
		s.close();
	}

	@Test
	public void testScrollingJoinFetchesSingleRowResultSet() {
		Session s = openSession();
		Transaction txn = s.beginTransaction();

		Animal mother = new Animal();
		mother.setDescription( "root-1" );

		Animal daughter = new Animal();
		daughter.setDescription( "daughter" );

		daughter.setMother( mother );
		mother.addOffspring( daughter );

		s.save( mother );
		s.save( daughter );

		txn.commit();
		s.close();

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

		assertNotNull(s
		        .createQuery( "from Animal a left join fetch a.offspring where a.description like :desc order by a.id" )
		        .setString( "desc", "root%" )
		        .uniqueResult() );

		ScrollableResults results = s
		        .createQuery( "from Animal a left join fetch a.offspring where a.description like :desc order by a.id" )
		        .setString( "desc", "root%" )
		        .scroll();

		assertFalse( results.isFirst() );
		assertFalse( results.isLast() );
		assertFalse( results.previous() );		

		assertTrue( results.next() );
		assertTrue( results.isFirst() );
		assertTrue( results.isLast() );

		assertFalse( results.next() );
		assertFalse( results.isFirst() );
		assertFalse( results.isLast() );

		assertTrue( results.previous() );
		assertTrue( results.isFirst() );
		assertTrue( results.isLast() );

		assertFalse( results.previous() );
		assertFalse( results.isFirst() );
		assertFalse( results.isLast() );

		assertTrue( results.next() );
		assertTrue( results.isFirst() );
		assertTrue( results.isLast() );

		results.beforeFirst();
		assertFalse( results.isFirst() );
		assertFalse( results.isLast() );
		assertFalse( results.previous() );

		assertTrue( results.first() );
		assertTrue( results.isFirst() );
		assertTrue( results.isLast() );
		assertFalse( results.next() );

		results.afterLast();
		assertFalse( results.isFirst() );
		assertFalse( results.isLast() );
		assertFalse( results.next() );

		assertTrue( results.last() );
		assertTrue( results.isFirst() );
		assertTrue( results.isLast() );
		assertFalse( results.next() );

		assertTrue( results.first() );
		assertTrue( results.isFirst() );
		assertTrue( results.isLast() );		

		for ( int i=1; i<3; i++ ) {
			assertTrue( results.setRowNumber( 1 ) );
			assertTrue( results.isFirst() );
			assertTrue( results.isLast() );

			assertFalse( results.scroll( i ) );
			assertFalse( results.isFirst() );
			assertFalse( results.isLast() );

			assertTrue( results.setRowNumber( 1 ) );
			assertTrue( results.isFirst() );
			assertTrue( results.isLast() );

			assertFalse( results.scroll( - i ) );
			assertFalse( results.isFirst() );
			assertFalse( results.isLast() );

			if ( i != 1 ) {
				assertFalse( results.setRowNumber( i ) );
				assertFalse( results.isFirst() );
				assertFalse( results.isLast() );

				assertFalse( results.setRowNumber( - i ) );
				assertFalse( results.isFirst() );
				assertFalse( results.isLast() );
			}
		}

		txn.commit();
		s.close();

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

		s.createQuery( "delete Animal where not description like 'root%'" ).executeUpdate();
		s.createQuery( "delete Animal" ).executeUpdate();

		txn.commit();
		s.close();
	}

	@Test
	@RequiresDialectFeature(
			value = DialectChecks.SupportsResultSetPositioningOnForwardOnlyCursorCheck.class,
			comment = "Driver does not support result set positioning  methods on forward-only cursors"
	)
	public void testScrollingJoinFetchesForward() {
		TestData data = new TestData();
		data.prepare();

		Session s = openSession();
		Transaction txn = s.beginTransaction();

		ScrollableResults results = s
		        .createQuery( "from Animal a left join fetch a.offspring where a.description like :desc order by a.id" )
		        .setString( "desc", "root%" )
				.scroll( ScrollMode.FORWARD_ONLY );

		int counter = 0;
		while ( results.next() ) {
			counter++;
			Animal animal = ( Animal ) results.get( 0 );
			checkResult( animal );
		}
		assertEquals( "unexpected result count", 2, counter );

		txn.commit();
		s.close();

		data.cleanup();
	}

	@Test
	public void testScrollingJoinFetchesReverse() {
		TestData data = new TestData();
		data.prepare();

		Session s = openSession();
		Transaction txn = s.beginTransaction();

		ScrollableResults results = s
		        .createQuery( "from Animal a left join fetch a.offspring where a.description like :desc order by a.id" )
		        .setString( "desc", "root%" )
		        .scroll();

		results.afterLast();

		int counter = 0;
		while ( results.previous() ) {
			counter++;
			Animal animal = ( Animal ) results.get( 0 );
			checkResult( animal );
		}
		assertEquals( "unexpected result count", 2, counter );

		txn.commit();
		s.close();

		data.cleanup();
	}

	@Test
	public void testScrollingJoinFetchesPositioning() {
		TestData data = new TestData();
		data.prepare();

		Session s = openSession();
		Transaction txn = s.beginTransaction();

		ScrollableResults results = s
		        .createQuery( "from Animal a left join fetch a.offspring where a.description like :desc order by a.id" )
		        .setString( "desc", "root%" )
		        .scroll();

		results.first();
		Animal animal = ( Animal ) results.get( 0 );
		assertEquals( "first() did not return expected row", data.root1Id, animal.getId() );

		results.scroll( 1 );
		animal = ( Animal ) results.get( 0 );
		assertEquals( "scroll(1) did not return expected row", data.root2Id, animal.getId() );

		results.scroll( -1 );
		animal = ( Animal ) results.get( 0 );
		assertEquals( "scroll(-1) did not return expected row", data.root1Id, animal.getId() );

		results.setRowNumber( 1 );
		animal = ( Animal ) results.get( 0 );
		assertEquals( "setRowNumber(1) did not return expected row", data.root1Id, animal.getId() );

		results.setRowNumber( 2 );
		animal = ( Animal ) results.get( 0 );
		assertEquals( "setRowNumber(2) did not return expected row", data.root2Id, animal.getId() );

		txn.commit();
		s.close();

		data.cleanup();
	}

	private void checkResult(Animal animal) {
		if ( "root-1".equals( animal.getDescription() ) ) {
			assertEquals( "root-1 did not contain both children", 2, animal.getOffspring().size() );
		}
		else if ( "root-2".equals( animal.getDescription() ) ) {
			assertEquals( "root-2 did not contain zero children", 0, animal.getOffspring().size() );
		}
	}

	private class TestData {

		private Long root1Id;
		private Long root2Id;

		private void prepare() {
			Session s = openSession();
			Transaction txn = s.beginTransaction();

			Animal mother = new Animal();
			mother.setDescription( "root-1" );

			Animal another = new Animal();
			another.setDescription( "root-2" );

			Animal son = new Animal();
			son.setDescription( "son");

			Animal daughter = new Animal();
			daughter.setDescription( "daughter" );

			Animal grandson = new Animal();
			grandson.setDescription( "grandson" );

			Animal grandDaughter = new Animal();
			grandDaughter.setDescription( "granddaughter" );

			son.setMother( mother );
			mother.addOffspring( son );

			daughter.setMother( mother );
			mother.addOffspring( daughter );

			grandson.setMother( daughter );
			daughter.addOffspring( grandson );

			grandDaughter.setMother( daughter );
			daughter.addOffspring( grandDaughter );

			s.save( mother );
			s.save( another );
			s.save( son );
			s.save( daughter );
			s.save( grandson );
			s.save( grandDaughter );

			txn.commit();
			s.close();

			root1Id = mother.getId();
			root2Id = another.getId();
		}

		private void cleanup() {
			Session s = openSession();
			Transaction txn = s.beginTransaction();
			
			s.createQuery( "delete Animal where description like 'grand%'" ).executeUpdate();
			s.createQuery( "delete Animal where not description like 'root%'" ).executeUpdate();
			s.createQuery( "delete Animal" ).executeUpdate();

			txn.commit();
			s.close();
		}
	}
}