/*

  * 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.spi.impl;

 import java.lang.reflect.InvocationTargetException;

 import java.security.AccessController;

 import java.security.PrivilegedActionException;

 import java.security.PrivilegedExceptionAction;

 import java.util.List;

 import java.util.logging.Level;

 import java.util.logging.Logger;

 import javax.faces.FacesException;

 import javax.faces.context.ExternalContext;

 import org.apache.myfaces.shared.util.ClassUtils;

 import org.apache.myfaces.spi.ServiceProviderFinderFactory;

 import org.apache.myfaces.spi.WebConfigProvider;

 import org.apache.myfaces.spi.WebConfigProviderFactory;

 /**

  * The default implementation of WebXmlProviderFactory. Looks for META-INF/service

  * entries of org.apache.myfaces.shared.spi.WebXmlProvider.

  *

  * Returns a new DefaultWebXmlProvider if no custom impl can be found.

  *

  * @author Jakob Korherr

  * @since 2.0.3

  */

 public class DefaultWebConfigProviderFactory extends WebConfigProviderFactory

 {

     public static final String WEB_CONFIG_PROVIDER = WebConfigProvider.class.getName();

     public static final String WEB_CONFIG_PROVIDER_LIST = WebConfigProvider.class.getName()+".LIST";

     private Logger getLogger()

     {

         return Logger.getLogger(DefaultWebConfigProviderFactory.class.getName());

     }

     @Override

     public WebConfigProvider getWebConfigProvider(ExternalContext externalContext)

     {

         WebConfigProvider returnValue = null;

         final ExternalContext extContext = externalContext;

         try

         {

             if (System.getSecurityManager() != null)

             {

                 returnValue = AccessController.doPrivileged(new PrivilegedExceptionAction<WebConfigProvider>()

                         {

                             public WebConfigProvider run() throws ClassNotFoundException,

                                     NoClassDefFoundError,

                                     InstantiationException,

                                     IllegalAccessException,

                                     InvocationTargetException,

                                     PrivilegedActionException

                             {

                                 return resolveWebXmlProviderFromService(extContext);

                             }

                         });

             }

             else

             {

                 returnValue = resolveWebXmlProviderFromService(extContext);

             }

         }

         catch (ClassNotFoundException e)

         {

             // ignore

         }

         catch (NoClassDefFoundError e)

         {

             // ignore

         }

         catch (InstantiationException e)

         {

             getLogger().log(Level.SEVERE, "", e);

         }

         catch (IllegalAccessException e)

         {

             getLogger().log(Level.SEVERE, "", e);

         }

         catch (InvocationTargetException e)

         {

             getLogger().log(Level.SEVERE, "", e);

         }

         catch (PrivilegedActionException e)

         {

             throw new FacesException(e);

         }

         return returnValue;

     }

     private WebConfigProvider resolveWebXmlProviderFromService(

             ExternalContext externalContext) throws ClassNotFoundException,

             NoClassDefFoundError,

             InstantiationException,

             IllegalAccessException,

             InvocationTargetException,

             PrivilegedActionException

     {

         List<String> classList = (List<String>) externalContext.getApplicationMap().get(WEB_CONFIG_PROVIDER_LIST);

         if (classList == null)

         {

             classList = ServiceProviderFinderFactory.getServiceProviderFinder(externalContext).

                     getServiceProviderList(WEB_CONFIG_PROVIDER);

             externalContext.getApplicationMap().put(WEB_CONFIG_PROVIDER_LIST, classList);

         }

         return ClassUtils.buildApplicationObject(WebConfigProvider.class, classList, new DefaultWebConfigProvider());

     }

 }