Hibernate example source code file (SerializationHelperTest.java)

This example Hibernate source code file (SerializationHelperTest.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

baseunittestcase, class, classloader, classnotfoundexception, classnotfoundexception, could, customclassloader, customclassloader, exception, exception, io, object, object, serializable, throwable

The Hibernate SerializationHelperTest.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2010, 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.util;
import java.io.InputStream;
import java.io.Serializable;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertSame;

import org.hibernate.LockMode;
import org.hibernate.bytecode.spi.ByteCodeHelper;
import org.hibernate.internal.util.SerializationHelper;
import org.hibernate.testing.junit4.BaseUnitTestCase;

/**
 * This is basically a test to assert the expectations of {@link org.hibernate.type.SerializableType}
 * in regards to deserializing bytes from second level caches.
 *
 * @author Steve Ebersole
 */
public class SerializationHelperTest extends BaseUnitTestCase {
	private ClassLoader original;
	private CustomClassLoader custom;

	@Before
	public void setUp() throws Exception {
		original = Thread.currentThread().getContextClassLoader();
		custom = new CustomClassLoader( original );
		Thread.currentThread().setContextClassLoader( custom );
	}

	@After
	public void tearDown() throws Exception {
		Thread.currentThread().setContextClassLoader( original );
	}

	@Test
	public void testSerializeDeserialize() throws Exception {
		Class clazz = Thread.currentThread().getContextClassLoader().loadClass( "org.hibernate.test.util.SerializableThing" );
		Object instance = clazz.newInstance();

		// SerializableType.toBytes() logic, as called from SerializableType.disassemble()
		byte[] bytes = SerializationHelper.serialize( (Serializable) instance );

		// SerializableType.fromBytes() logic, as called from SerializableType.assemble
		//		NOTE : specifically we use Serializable.class.getClassLoader for the CL in many cases
		//			which are the problematic cases
		Object instance2 = SerializationHelper.deserialize( bytes, Serializable.class.getClassLoader() );

		assertEquals( instance.getClass(), instance2.getClass() );
		assertEquals( instance.getClass().getClassLoader(), instance2.getClass().getClassLoader() );
		assertEquals( custom, instance2.getClass().getClassLoader() );
	}

	public void testSerDeserClassUnknownToCustomLoader() throws Exception {
		Object instance = LockMode.OPTIMISTIC;
		assertSame( 
			SerializationHelper.hibernateClassLoader(),
			instance.getClass().getClassLoader() 
		);

		// SerializableType.toBytes() logic, as called from SerializableType.disassemble()
		byte[] bytes = SerializationHelper.serialize( (Serializable) instance );

		// SerializableType.fromBytes() logic, as called from SerializableType.assemble
		// NOTE : specifically we use custom so that LockType.class is not found
		//        until the 3rd loader (because loader1 == loader2, the custom classloader)
		Object instance2 = SerializationHelper.deserialize( bytes, custom );

		assertSame( instance.getClass(), instance2.getClass() );
		assertSame( instance.getClass().getClassLoader(), instance2.getClass().getClassLoader() );
	}


	public static class CustomClassLoader extends ClassLoader {
		public CustomClassLoader(ClassLoader parent) {
			super( parent );
		}

		public Class loadClass(String name) throws ClassNotFoundException {
			if ( name.equals( "org.hibernate.LockMode" ) ) {
				throw new ClassNotFoundException( "Could not find "+ name );
			}
			if ( ! name.equals( "org.hibernate.test.util.SerializableThing" ) ) {
				return getParent().loadClass( name );
			}

			Class c = findLoadedClass( name );
			if ( c != null ) {
				return c;
			}

			InputStream is = this.getResourceAsStream( name.replace( '.', '/' ) + ".class" );
			if ( is == null ) {
				throw new ClassNotFoundException( name + " not found" );
			}

			try {
				byte[] bytecode = ByteCodeHelper.readByteCode( is );
				return defineClass( name, bytecode, 0, bytecode.length );
			}
			catch( Throwable t ) {
				throw new ClassNotFoundException( name + " not found", t );
			}
		}
	}
}