/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 * 
 *  http://www.apache.org/licenses/LICENSE-2.0
 * 
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 */
package org.apache.myfaces.buildtools.maven2.plugin.javascript.jmt.compress;

import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.Collection;
import java.util.Iterator;

import org.apache.maven.artifact.Artifact;

/**
 * @author <a href="mailto:nicolas@apache.org">Nicolas De Loof</a>
 */
public class IsolatedClassLoader
    extends URLClassLoader
{

    public IsolatedClassLoader( Artifact artifact )
    {
        super( getArtifactURLs( artifact ) );
    }

    public IsolatedClassLoader( Collection artifacts )
    {
        super( getArtifactURLs( artifacts ) );
    }

    private static URL[] getArtifactURLs( Collection artifacts )
    {
        URL[] urls = new URL[artifacts.size()];
        try
        {
            int i = 0;
            for ( Iterator iterator = artifacts.iterator(); iterator.hasNext(); )
            {
                Artifact artifact = (Artifact) iterator.next();
                urls[i++] = artifact.getFile().toURL();
            }
        }
        catch ( MalformedURLException e )
        {
            return null;
        }
        return urls;
    }

    private static URL[] getArtifactURLs( Artifact artifact )
    {
        URL url;
        try
        {
            url = artifact.getFile().toURL();
            return new URL[] { url };
        }
        catch ( MalformedURLException e )
        {
            return null;
        }
    }

    public Class loadClass( String name )
        throws ClassNotFoundException
    {

        Class c = findLoadedClass( name );
        if ( c == null )
        {
            try
            {
                return findClass( name );
            }
            catch ( ClassNotFoundException e )
            {
                return super.loadClass( name );
            }
        }
        return super.loadClass( name );
    }

}