impl/src/main/java/org/apache/myfaces/spi/impl/DefaultFacesConfigurationProviderFactory.java

/*
 * 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 org.apache.myfaces.config.DefaultFacesConfigurationProvider;
import org.apache.myfaces.util.lang.ClassUtils;
import org.apache.myfaces.spi.FacesConfigurationProvider;
import org.apache.myfaces.spi.FacesConfigurationProviderFactory;
import org.apache.myfaces.spi.ServiceProviderFinderFactory;

import javax.faces.FacesException;
import javax.faces.context.ExternalContext;
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;

/**
 * 
 * @author Leonardo Uribe
 * @since 2.0.3
 */
public class DefaultFacesConfigurationProviderFactory extends FacesConfigurationProviderFactory
{

    public static final String FACES_CONFIGURATION_PROVIDER = FacesConfigurationProvider.class.getName();
    
    public static final String FACES_CONFIGURATION_PROVIDER_LIST = FacesConfigurationProvider.class.getName()+".LIST";
    
    public static final String FACES_CONFIGURATION_PROVIDER_INSTANCE_KEY
            = FacesConfigurationProvider.class.getName() + ".INSTANCE";

    private Logger getLogger()
    {
        return Logger.getLogger(DefaultFacesConfigurationProviderFactory.class.getName());
    }

    @Override
    public FacesConfigurationProvider getFacesConfigurationProvider(ExternalContext externalContext)
    {
        FacesConfigurationProvider returnValue = (FacesConfigurationProvider)
                externalContext.getApplicationMap().get(FACES_CONFIGURATION_PROVIDER_INSTANCE_KEY);
        if (returnValue == null)
        {
            final ExternalContext extContext = externalContext;
            try
            {
                if (System.getSecurityManager() != null)
                {
                    returnValue = (FacesConfigurationProvider) AccessController.doPrivileged(
                            (PrivilegedExceptionAction) () -> resolveFacesConfigurationProviderFromService(extContext));
                }
                else
                {
                    returnValue = resolveFacesConfigurationProviderFromService(extContext);
                }
            }
            catch (ClassNotFoundException | NoClassDefFoundError | InstantiationException | IllegalAccessException
                    | InvocationTargetException e)
            {
                getLogger().log(Level.SEVERE, "", e);
            }
            catch (PrivilegedActionException e)
            {
                throw new FacesException(e);
            }
        }
        
        if (returnValue == null)
        {
            returnValue = new DefaultFacesConfigurationProvider();
        }

        externalContext.getApplicationMap().put(FACES_CONFIGURATION_PROVIDER_INSTANCE_KEY, returnValue);

        return returnValue;
    }

    private FacesConfigurationProvider resolveFacesConfigurationProviderFromService(
            ExternalContext externalContext) throws ClassNotFoundException,
            NoClassDefFoundError,
            InstantiationException,
            IllegalAccessException,
            InvocationTargetException,
            PrivilegedActionException
    {
        List<String> classList = (List<String>)
                externalContext.getApplicationMap().get(FACES_CONFIGURATION_PROVIDER_LIST);
        if (classList == null)
        {
            classList = ServiceProviderFinderFactory.getServiceProviderFinder(externalContext).
                    getServiceProviderList(FACES_CONFIGURATION_PROVIDER);
            externalContext.getApplicationMap().put(FACES_CONFIGURATION_PROVIDER_LIST, classList);
        }

        return ClassUtils.buildApplicationObject(FacesConfigurationProvider.class, classList,
                                                 new DefaultFacesConfigurationProvider());
    }
}