/*

  * 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.config.util;

 import java.io.IOException;

 import java.net.JarURLConnection;

 import java.net.URL;

 import java.net.URLConnection;

 import java.util.jar.JarFile;

 /**

  *

  * @author Leonardo Uribe

  */

 public class JarUtils

 {

     public static JarFile getJarFile(URL url) throws IOException

     {

         URLConnection conn = url.openConnection();

         conn.setUseCaches(false);

         conn.setDefaultUseCaches(false);

         JarFile jarFile;

         if (conn instanceof JarURLConnection)

         {

             jarFile = ((JarURLConnection) conn).getJarFile();

         }

         else

         {

             jarFile = _getAlternativeJarFile(url);

         }

         return jarFile;

     }

     /**

      * taken from org.apache.myfaces.view.facelets.util.Classpath

      * 

      * For URLs to JARs that do not use JarURLConnection - allowed by the servlet spec - attempt to produce a JarFile

      * object all the same. Known servlet engines that function like this include Weblogic and OC4J. This is not a full

      * solution, since an unpacked WAR or EAR will not have JAR "files" as such.

      */

     private static JarFile _getAlternativeJarFile(URL url) throws IOException

     {

         String urlFile = url.getFile();

         // Trim off any suffix - which is prefixed by "!/" on Weblogic

         int separatorIndex = urlFile.indexOf("!/");

         // OK, didn't find that. Try the less safe "!", used on OC4J

         if (separatorIndex == -1)

         {

             separatorIndex = urlFile.indexOf('!');

         }

         if (separatorIndex != -1)

         {

             String jarFileUrl = urlFile.substring(0, separatorIndex);

             // And trim off any "file:" prefix.

             if (jarFileUrl.startsWith("file:"))

             {

                 jarFileUrl = jarFileUrl.substring("file:".length());

             }

             return new JarFile(jarFileUrl);

         }

         return null;

     }

 }