package org.apache.maven.surefire.booter;

 /*

  * 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.

  */

 import java.net.URL;

 import java.net.URLClassLoader;

 import java.util.HashSet;

 import java.util.Set;

 /**

  * @noinspection CustomClassloader

  */

 public class IsolatedClassLoader

     extends URLClassLoader

 {

     private final ClassLoader parent = ClassLoader.getSystemClassLoader();

     private final Set urls = new HashSet();

     private boolean childDelegation = true;

     private static final URL[] EMPTY_URL_ARRAY = new URL[0];

     public IsolatedClassLoader( ClassLoader parent, boolean childDelegation )

     {

         super( EMPTY_URL_ARRAY, parent );

         this.childDelegation = childDelegation;

     }

     public void addURL( URL url )

     {

         // avoid duplicates

         if ( !urls.contains( url ) )

         {

             super.addURL( url );

             urls.add( url );

         }

     }

     public synchronized Class loadClass( String name )

         throws ClassNotFoundException

     {

         Class c;

         if ( childDelegation )

         {

             c = findLoadedClass( name );

             ClassNotFoundException ex = null;

             if ( c == null )

             {

                 try

                 {

                     c = findClass( name );

                 }

                 catch ( ClassNotFoundException e )

                 {

                     ex = e;

                     if ( parent != null )

                     {

                         c = parent.loadClass( name );

                     }

                 }

             }

             if ( c == null )

             {

                 throw ex;

             }

         }

         else

         {

             c = super.loadClass( name );

         }

         return c;

     }

 }