/*
 * GNU LESSER GENERAL PUBLIC LICENSE Copyright (C) 2006 The Lobo Project
 * 
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 * 
 * This library 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 library; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 * 
 * Contact info: lobochief@users.sourceforge.net
 */
/*
 * Created on Jun 19, 2005
 */
package com.nvarghese.beowulf.common.cobra.util;

import java.util.Collection;

/**
 * @author J. H. S.
 */
public abstract class MultiplexClassLoader extends BaseClassLoader {

	private static final BaseClassLoader[] EMPTY_CLASS_LOADERS = new BaseClassLoader[0];
	private final BaseClassLoader[] parentLoaders;

	/**
	 * @param parent
	 */
	public MultiplexClassLoader(final Collection classLoaders) {

		super(null);
		this.parentLoaders = (BaseClassLoader[]) classLoaders.toArray(EMPTY_CLASS_LOADERS);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see java.lang.ClassLoader#loadClass(java.lang.String, boolean)
	 */
	public synchronized Class loadClass(final String name, final boolean resolve) throws ClassNotFoundException {

		// First, check if the class has already been loaded
		Class c = findLoadedClass(name);
		if (c == null) {
			try {
				int len = this.parentLoaders.length;
				if (len == 0) {
					c = findSystemClass(name);
				} else {
					for (int i = 0; i < len; i++) {
						BaseClassLoader parent = this.parentLoaders[i];
						try {
							c = parent.loadClass(name, false);
							if (c != null) {
								return c;
							}
						} catch (ClassNotFoundException cnfe) {
							// ignore
						}
					}
				}
			} catch (ClassNotFoundException e) {
				// If still not found, then invoke findClass in order
				// to find the class.
				c = findClass(name);
			}
			if (c == null) {
				c = findClass(name);
			}
		}
		if (resolve) {
			resolveClass(c);
		}
		return c;
	}
}