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Hibernate example source code file (ClassLoaderServiceImpl.java)

This example Hibernate source code file (ClassLoaderServiceImpl.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

arraylist, class, classloader, classloader, classloaderserviceimpl, classloaderserviceimpl, enumeration, exception, exception, io, linkedhashset, net, network, override, override, t, url, util

The Hibernate ClassLoaderServiceImpl.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.service.classloading.internal;

import java.io.InputStream;
import java.net.URL;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;

import org.hibernate.cfg.AvailableSettings;
import org.hibernate.service.classloading.spi.ClassLoaderService;
import org.hibernate.service.classloading.spi.ClassLoadingException;

/**
 * Standard implementation of the service for interacting with class loaders
 *
 * @author Steve Ebersole
 */
public class ClassLoaderServiceImpl implements ClassLoaderService {
	private final LinkedHashSet<ClassLoader> classLoadingClassLoaders;
	private final ClassLoader resourcesClassLoader;

	public ClassLoaderServiceImpl(Map configVales) {
		this( determineClassLoaders( configVales ) );
	}

	private ClassLoaderServiceImpl(ClassLoader... classLoaders) {
		this( classLoaders[0], classLoaders[1], classLoaders[2], classLoaders[3] );
	}

	private static ClassLoader[] determineClassLoaders(Map configVales) {
		ClassLoader applicationClassLoader = (ClassLoader) configVales.get( AvailableSettings.APP_CLASSLOADER );
		ClassLoader resourcesClassLoader = (ClassLoader) configVales.get( AvailableSettings.RESOURCES_CLASSLOADER );
		ClassLoader hibernateClassLoader = (ClassLoader) configVales.get( AvailableSettings.HIBERNATE_CLASSLOADER );
		ClassLoader environmentClassLoader = (ClassLoader) configVales.get( AvailableSettings.ENVIRONMENT_CLASSLOADER );

		if ( hibernateClassLoader == null ) {
			hibernateClassLoader = ClassLoaderServiceImpl.class.getClassLoader();
		}

		if ( environmentClassLoader == null || applicationClassLoader == null ) {
			ClassLoader sysClassLoader = locateSystemClassLoader();
			ClassLoader tccl = locateTCCL();
			if ( environmentClassLoader == null ) {
				environmentClassLoader = sysClassLoader != null ? sysClassLoader : hibernateClassLoader;
			}
			if ( applicationClassLoader == null ) {
				applicationClassLoader = tccl != null ? tccl : hibernateClassLoader;
			}
		}

		if ( resourcesClassLoader == null ) {
			resourcesClassLoader = applicationClassLoader;
		}

		return new ClassLoader[] {
			applicationClassLoader,
			resourcesClassLoader,
			hibernateClassLoader,
			environmentClassLoader
		};
	}

	private static ClassLoader locateSystemClassLoader() {
		try {
			return ClassLoader.getSystemClassLoader();
		}
		catch ( Exception e ) {
			return null;
		}
	}

	private static ClassLoader locateTCCL() {
		try {
			return Thread.currentThread().getContextClassLoader();
		}
		catch ( Exception e ) {
			return null;
		}
	}

	public ClassLoaderServiceImpl(ClassLoader classLoader) {
		this( classLoader, classLoader, classLoader, classLoader );
	}

	public ClassLoaderServiceImpl(
			ClassLoader applicationClassLoader,
			ClassLoader resourcesClassLoader,
			ClassLoader hibernateClassLoader,
			ClassLoader environmentClassLoader) {
		this.classLoadingClassLoaders = new LinkedHashSet<ClassLoader>();
		classLoadingClassLoaders.add( applicationClassLoader );
		classLoadingClassLoaders.add( hibernateClassLoader );
		classLoadingClassLoaders.add( environmentClassLoader );

		this.resourcesClassLoader = resourcesClassLoader;
	}

	@Override
	@SuppressWarnings( {"unchecked"})
	public <T> Class classForName(String className) {
		for ( ClassLoader classLoader : classLoadingClassLoaders ) {
			try {
				return (Class<T>) classLoader.loadClass( className );
			}
			catch ( Exception ignore) {
			}
		}
		throw new ClassLoadingException( "Unable to load class [" + className + "]" );
	}

	@Override
	public URL locateResource(String name) {
		// first we try name as a URL
		try {
			return new URL( name );
		}
		catch ( Exception ignore ) {
		}

		try {
			return resourcesClassLoader.getResource( name );
		}
		catch ( Exception ignore ) {
		}

		return null;
	}

	@Override
	public InputStream locateResourceStream(String name) {
		// first we try name as a URL
		try {
			return new URL( name ).openStream();
		}
		catch ( Exception ignore ) {
		}

		try {
			return resourcesClassLoader.getResourceAsStream( name );
		}
		catch ( Exception ignore ) {
		}

		return null;
	}

	@Override
	public List<URL> locateResources(String name) {
		ArrayList<URL> urls = new ArrayList();
		try {
			Enumeration<URL> urlEnumeration = resourcesClassLoader.getResources( name );
			if ( urlEnumeration != null && urlEnumeration.hasMoreElements() ) {
				while ( urlEnumeration.hasMoreElements() ) {
					urls.add( urlEnumeration.nextElement() );
				}
			}
		}
		catch ( Exception ignore ) {
		}

		return urls;
	}

}

Other Hibernate examples (source code examples)

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