Hibernate example source code file (Cloneable.java)

This example Hibernate source code file (Cloneable.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

bean, beaninfo, hibernateexception, hibernateexception, introspectionexception, javabean, listener, object, object, privilegedaction, propertydescriptor, reader_method_args, reader_method_args, security, throwable, unable, unable

The Hibernate Cloneable.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008, Red Hat Middleware LLC 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 Middleware LLC.
 *
 * 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.internal.util;

import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.security.AccessController;
import java.security.PrivilegedAction;
import org.hibernate.HibernateException;

/**
 * An object that is shallow-coneable
 * 
 * @author Steve Ebersole
 */
public class Cloneable {
	
	private static final Object[] READER_METHOD_ARGS = new Object[0];

	/**
	 * Essentially performs a shallow copy of this SessionEventListenerConfig
	 * instance; meaning the SessionEventListenerConfig itself is cloned, but
	 * the individual listeners are <b>not cloned.
	 *
	 * @return The SessionEventListenerConfig shallow copy.
	 */
	public Object shallowCopy() {
		return AccessController.doPrivileged(
		        new PrivilegedAction() {
			        public Object run() {
				        return copyListeners();
			        }
		        }
			);
	}

	/**
	 * Checks to ensure the SessionEventListenerConfig is fully
	 * configured (basically, that none of the listeners is null).
	 *
	 * @throws HibernateException If the SessionEventListenerConfig
	 * is not fully configured.
	 */
	public void validate() throws HibernateException {
		AccessController.doPrivileged(
		        new PrivilegedAction() {
			        public Object run() {
				        checkListeners();
				        return null;
			        }
		        }
			);

	}

	private Object copyListeners() {
		Object copy = null;
		BeanInfo beanInfo = null;
		try {
			beanInfo = Introspector.getBeanInfo( getClass(), Object.class );
			internalCheckListeners( beanInfo );
			copy = getClass().newInstance();
			PropertyDescriptor[] pds = beanInfo.getPropertyDescriptors();
			for ( int i = 0, max = pds.length; i < max; i++ ) {
				try {
					pds[i].getWriteMethod().invoke(
							copy,
							new Object[] {
								pds[i].getReadMethod().invoke( this, READER_METHOD_ARGS )
							}
						);
				}
				catch( Throwable t ) {
					throw new HibernateException( "Unable copy copy listener [" + pds[i].getName() + "]" );
				}
			}
		}
		catch( Exception t ) {
			throw new HibernateException( "Unable to copy listeners", t );
		}
		finally {
			if ( beanInfo != null ) {
				// release the jdk internal caches everytime to ensure this
				// plays nicely with destroyable class-loaders
				Introspector.flushFromCaches( getClass() );
			}
		}
		
		return copy;
	}

	private void checkListeners() {
		BeanInfo beanInfo = null;
		try {
			beanInfo = Introspector.getBeanInfo( getClass(), Object.class );
			internalCheckListeners( beanInfo );
		}
		catch( IntrospectionException t ) {
			throw new HibernateException( "Unable to validate listener config", t );
		}
		finally {
			if ( beanInfo != null ) {
				// release the jdk internal caches everytime to ensure this
				// plays nicely with destroyable class-loaders
				Introspector.flushFromCaches( getClass() );
			}
		}
	}

	private void internalCheckListeners(BeanInfo beanInfo) {
		PropertyDescriptor[] pds = beanInfo.getPropertyDescriptors();
		try {
			for ( int i = 0, max = pds.length; i < max; i++ ) {
				final Object listener = pds[i].getReadMethod().invoke( this, READER_METHOD_ARGS );
				if ( listener == null ) {
					throw new HibernateException( "Listener [" + pds[i].getName() + "] was null" );
				}
				if ( listener.getClass().isArray() ) {
					Object[] listenerArray = (Object[]) listener;
					int length = listenerArray.length;
					for ( int index = 0 ; index < length ; index++ ) {
						if ( listenerArray[index] == null ) {
							throw new HibernateException( "Listener in [" + pds[i].getName() + "] was null" );
						}
					}
				}
			}
		}
		catch( HibernateException e ) {
			throw e;
		}
		catch( Throwable t ) {
			throw new HibernateException( "Unable to validate listener config" );
		}
	}
	
}