Hibernate example source code file (BackrefTest.java)

This example Hibernate source code file (BackrefTest.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

blase, child, child, elvira, elvira, marc, nathalie, override, parent, parent, session, string, string, test

The Hibernate BackrefTest.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.unidir;

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;

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

	@Override
	public String getCacheConcurrencyStrategy() {
		return null;
	}

	@Test
	public void testBackRef() {
		Session s = openSession();
		Transaction t = s.beginTransaction();
		Parent p = new Parent("Marc");
		Parent p2 = new Parent("Nathalie");
		Child c = new Child("Elvira");
		Child c2 = new Child("Blase");
		p.getChildren().add(c);
		p.getChildren().add(c2);
		s.persist(p);
		s.persist(p2);
		t.commit();
		s.close();

		s = openSession();
		t = s.beginTransaction();
		c = (Child) s.get(Child.class, "Elvira");
		c.setAge(2);
		t.commit();
		s.close();

		s = openSession();
		t = s.beginTransaction();
		p = (Parent) s.get(Parent.class, "Marc");
		c = (Child) s.get(Child.class, "Elvira");
		c.setAge(18);
		t.commit();
		s.close();

		s = openSession();
		t = s.beginTransaction();
		p = (Parent) s.get(Parent.class, "Marc");
		p2 = (Parent) s.get(Parent.class, "Nathalie");
		c = (Child) s.get(Child.class, "Elvira");
		assertEquals( p.getChildren().indexOf(c), 0 );
		p.getChildren().remove(c);
		p2.getChildren().add(c);
		t.commit();

		s.close();
		s = openSession();
		t = s.beginTransaction();
		Parent p3 = new Parent("Marion");
		p3.getChildren().add( new Child("Gavin") );
		s.merge(p3);
		t.commit();
		s.close();

		s = openSession();
		t = s.beginTransaction();
		s.createQuery( "delete from Child" ).executeUpdate();
		s.createQuery( "delete from Parent" ).executeUpdate();
		t.commit();
		s.close();
	}

	@Test
	public void testBackRefToProxiedEntityOnMerge() {
		Session s = openSession();
		s.beginTransaction();
		Parent me = new Parent( "Steve" );
		me.getChildren().add( new Child( "Joe" ) );
  		s.persist( me );
		s.getTransaction().commit();
		s.close();

		// while detached, add a new element
		me.getChildren().add( new Child( "Cece" ) );
		me.getChildren().add( new Child( "Austin" ) );

		s = openSession();
		s.beginTransaction();
		// load 'me' to associate it with the new session as a proxy (this may have occurred as 'prior work'
		// to the reattachment below)...
		Object meProxy = s.load( Parent.class, me.getName() );
		assertFalse( Hibernate.isInitialized( meProxy ) );
		// now, do the reattchment...
		s.merge( me );
		s.getTransaction().commit();
		s.close();

		s = openSession();
		s.beginTransaction();
		s.createQuery( "delete from Child" ).executeUpdate();
		s.createQuery( "delete from Parent" ).executeUpdate();
		s.getTransaction().commit();
		s.close();
	}
}