package org.apache.maven.j2ee;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2002 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache Maven" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
 *    written permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache Maven", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 * ====================================================================
 */

import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.jar.JarEntry;

/**
 * A {@link ClassLoader} that loads classes from a {@link WarFile}
 *
 * @author <a href="mailto:dion@multitask.com.au">dIon Gillard</a>
 * @version $Id: WarClassLoader.java,v 1.1 2003/01/24 03:45:17 jvanzyl Exp $
 */
public class WarClassLoader extends URLClassLoader
{
    /** temp files created by classloader */
    private List tempFiles = new ArrayList();
    /** war file to be used for class loading */
    private WarFile war;
    
    /**
     * Creates a new instance of WarClassLoader
     * 
     * @param war a {@link WarFile}
     * @throws IOException when an I/O error occurs extracting the jars from the
     *         war
     * @throws MalformedURLException if the jar: URL is not supported on the
     *         underlying platform
     */
    public WarClassLoader(WarFile war) throws IOException, MalformedURLException
    {
        super (new URL[0]);
        this.war = war;
        addURLs();
    }
    
    /**
     * Creates a new instance of WarClassLoader with the provided parent 
     * classloader as the one to delegate to if classes can't be found
     * 
     * @param war a {@link WarFile}
     * @param classloader a {@link ClassLoader} to delegate to.
     * @throws IOException when an I/O error occurs extracting the jars from
     *      the war
     * @throws MalformedURLException if the jar: URL is not supported on the
     *      underlying platform
     */
    public WarClassLoader(WarFile war, ClassLoader classloader) throws
        IOException, MalformedURLException
    {
        super(new URL[0], classloader);
        this.war = war;
        addURLs();
    }
    
    /**
     * Add WEB-INF/classes and WEB-INF/lib/*.jar as extra classpath URLs
     * 
     * @throws IOException when an I/O error occurs extracting the jars from
     *      the war
     * @throws MalformedURLException if the jar: URL is not supported on the
     *      underlying platform
     */
    private void addURLs() throws IOException, MalformedURLException
    {
        File warFile = new File(war.getName());
        URL webInfClasses = new URL("jar:" + warFile.toURL() + "!/"
            + "WEB-INF/classes/");
        addURL(webInfClasses);
        Set jars = war.getLibEntries();
        JarEntry entry = null;
        for (Iterator jarEntries = jars.iterator(); jarEntries.hasNext();)
        {
            entry = (JarEntry) jarEntries.next();
            File jar = war.extract(entry);
            tempFiles.add(jar);
            jar.deleteOnExit();
            addURL(new URL("jar:" + jar.toURL() + "!/"));
        }
    }
}
