package org.codehaus.mojo.javascript.compress;
   
   /*
    * Copyright 2001-2005 The Apache Software Foundation.
    *
    * Licensed 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.
   */
  
  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, ClassLoader parent )
      {
          super( getArtifactURLs( artifact ), parent );
      }
  
      public IsolatedClassLoader( Collection artifacts, ClassLoader parent )
      {
          super( getArtifactURLs( artifacts ), parent );
      }
  
      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 );
      }
  
  }