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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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/*
 * Copyright 2005-2014 Red Hat, Inc.
 * Red Hat 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.hornetq.utils;

import java.net.URL;

/**
 * This class will be used to perform generic class-loader operations,
 * such as load a class first using TCCL, and then the classLoader used by HornetQ (ClassloadingUtil.getClass().getClassLoader()).
 * 
 * Is't required to use a Security Block on any calls to this class.
 *
 * @author Howard Gao
 */

public final class ClassloadingUtil
{
   private static final String INSTANTIATION_EXCEPTION_MESSAGE =
      "Your class must have a constructor without arguments. If it is an inner class, it must be static!";

   public static Object newInstanceFromClassLoader(final String className)
   {
      ClassLoader loader = ClassloadingUtil.class.getClassLoader();
      try
      {
         Class clazz = loader.loadClass(className);
         return clazz.newInstance();
      }
      catch (Throwable t)
      {
         if (t instanceof InstantiationException)
         {
            System.out.println(INSTANTIATION_EXCEPTION_MESSAGE);
         }
         loader = Thread.currentThread().getContextClassLoader();
         if (loader == null)
            throw new RuntimeException("No local context classloader", t);

         try
         {
            return loader.loadClass(className).newInstance();
         }
         catch (InstantiationException e)
         {
            throw new RuntimeException(INSTANTIATION_EXCEPTION_MESSAGE + " " + className, e);
         }
         catch (ClassNotFoundException e)
         {
            throw new IllegalStateException(e);
         }
         catch (IllegalAccessException e)
         {
            throw new RuntimeException(e);
         }
      }
   }

   public static Object newInstanceFromClassLoader(final String className, Object... objs)
   {
      ClassLoader loader = ClassloadingUtil.class.getClassLoader();
      try
      {
         Class[] parametersType = new Class[objs.length];
         for (int i = 0; i < objs.length; i++)
         {
            parametersType[i] = objs[i].getClass();
         }
         Class clazz = loader.loadClass(className);
         return clazz.getConstructor(parametersType).newInstance(objs);
      }
      catch (Throwable t)
      {
         if (t instanceof InstantiationException)
         {
            System.out.println(INSTANTIATION_EXCEPTION_MESSAGE);
         }
         loader = Thread.currentThread().getContextClassLoader();
         if (loader == null)
            throw new RuntimeException("No local context classloader", t);

         try
         {
            return loader.loadClass(className).newInstance();
         }
         catch (InstantiationException e)
         {
            throw new RuntimeException(INSTANTIATION_EXCEPTION_MESSAGE + " " + className, e);
         }
         catch (ClassNotFoundException e)
         {
            throw new IllegalStateException(e);
         }
         catch (IllegalAccessException e)
         {
            throw new RuntimeException(e);
         }
      }
   }

   public static URL findResource(final String resourceName)
   {
      ClassLoader loader = ClassloadingUtil.class.getClassLoader();
      try
      {
         URL resource = loader.getResource(resourceName);
         if (resource != null)
            return resource;
      }
      catch (Throwable t)
      {
      }

      loader = Thread.currentThread().getContextClassLoader();
      if (loader == null)
         return null;

      return loader.getResource(resourceName);
   }
}