api/src/main/java/javax/faces/webapp/FacesServlet.java - myfaces - Git at Google

 /*
  * 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 javax.faces.webapp;

 import java.io.IOException;
 import java.lang.reflect.Method;
 import java.lang.reflect.InvocationTargetException;
 import java.util.List;

 import javax.faces.FactoryFinder;
 import javax.faces.FacesException;
 import javax.faces.context.FacesContext;
 import javax.faces.context.FacesContextFactory;
 import javax.faces.lifecycle.Lifecycle;
 import javax.faces.lifecycle.LifecycleFactory;
 import javax.servlet.Servlet;
 import javax.servlet.ServletConfig;
 import javax.servlet.ServletException;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;

 /**
  * see Javadoc of <a href="http://java.sun.com/j2ee/javaserverfaces/1.1_01/docs/api/index.html">JSF Specification</a>
  *
  * @author Manfred Geiler (latest modification by $Author$)
  * @version $Revision$ $Date$
  */
 public final class FacesServlet
         implements Servlet
 {
     private static final Log log = LogFactory.getLog(FacesServlet.class);
     public static final String CONFIG_FILES_ATTR = "javax.faces.CONFIG_FILES";
     public static final String LIFECYCLE_ID_ATTR = "javax.faces.LIFECYCLE_ID";

     private static final String SERVLET_INFO = "FacesServlet of the MyFaces API implementation";
     private static final String ERROR_HANDLING_PARAMETER = "org.apache.myfaces.ERROR_HANDLING";
     private static final String ERROR_HANDLER_PARAMETER = "org.apache.myfaces.ERROR_HANDLER";
     private static final String ERROR_HANDLING_EXCEPTION_LIST = "org.apache.myfaces.errorHandling.exceptionList";

     private ServletConfig _servletConfig;
     private FacesContextFactory _facesContextFactory;
     private Lifecycle _lifecycle;

     public FacesServlet()
     {
         super();
     }

     public void destroy()
     {
         _servletConfig = null;
         _facesContextFactory = null;
         _lifecycle = null;
         if(log.isTraceEnabled()) log.trace("destroy");
     }

     public ServletConfig getServletConfig()
     {
         return _servletConfig;
     }

     public String getServletInfo()
     {
         return SERVLET_INFO;
     }

     private String getLifecycleId()
     {
         String lifecycleId = _servletConfig.getServletContext().getInitParameter(LIFECYCLE_ID_ATTR);
         return lifecycleId != null ? lifecycleId : LifecycleFactory.DEFAULT_LIFECYCLE;
     }

     public void init(ServletConfig servletConfig)
             throws ServletException
     {
         if(log.isTraceEnabled()) log.trace("init begin");
         _servletConfig = servletConfig;
         _facesContextFactory = (FacesContextFactory)FactoryFinder.getFactory(FactoryFinder.FACES_CONTEXT_FACTORY);
         //TODO: null-check for Weblogic, that tries to initialize Servlet before ContextListener

         //Javadoc says: Lifecycle instance is shared across multiple simultaneous requests, it must be implemented in a thread-safe manner.
         //So we can acquire it here once:
         LifecycleFactory lifecycleFactory = (LifecycleFactory)FactoryFinder.getFactory(FactoryFinder.LIFECYCLE_FACTORY);
         _lifecycle = lifecycleFactory.getLifecycle(getLifecycleId());
         if(log.isTraceEnabled()) log.trace("init end");
     }

     public void service(ServletRequest request,
                         ServletResponse response)
             throws IOException,
                    ServletException
     {

         HttpServletRequest httpRequest = ((HttpServletRequest) request);
         String pathInfo = httpRequest.getPathInfo();

         // if it is a prefix mapping ...
         if (pathInfo != null
                 && (pathInfo.startsWith("/WEB-INF") || pathInfo
                         .startsWith("/META-INF")))
         {
             StringBuffer buffer = new StringBuffer();

             buffer.append(" Someone is trying to access a secure resource : ").append(pathInfo);
             buffer.append("\n remote address is ").append(httpRequest.getRemoteAddr());
             buffer.append("\n remote host is ").append(httpRequest.getRemoteHost());
             buffer.append("\n remote user is ").append(httpRequest.getRemoteUser());
             buffer.append("\n request URI is ").append(httpRequest.getRequestURI());

             log.warn(buffer.toString());

             // Why does RI return a 404 and not a 403, SC_FORBIDDEN ?

             ((HttpServletResponse) response)
                     .sendError(HttpServletResponse.SC_NOT_FOUND);
             return;
         }

         if(log.isTraceEnabled()) log.trace("service begin");
         FacesContext facesContext = prepareFacesContext(request, response);
         try {
             _lifecycle.execute(facesContext);

             if (!handleQueuedExceptions(facesContext))
             {
                 _lifecycle.render(facesContext);
             }
         }
         catch (Exception e)
         {
             handleLifecycleException(facesContext, e);
         }
         catch (Throwable e)
         {
             handleLifecycleThrowable(facesContext, e);
         }
         finally
         {
             facesContext.release();
         }
         if(log.isTraceEnabled()) log.trace("service end");
     }

     /**This method makes sure we see an exception page also
      * if an exception has been thrown in UIInput.updateModel();
      * In this method, according to the spec, we may not rethrow the
      * exception, so we add it to a list and process it here.
      *
      * Attention: if you use redirects, the exceptions will get lost - exactly
      * like in the case of FacesMessages. If you want them to be taken over to the
      * next request, you should try the redirect-tracker of MyFaces.
      *
      * @param facesContext
      * @throws javax.faces.FacesException
      */
     private boolean handleQueuedExceptions(FacesContext facesContext) throws IOException, ServletException {
         List li = (List)
                 facesContext.getExternalContext().getRequestMap().get(ERROR_HANDLING_EXCEPTION_LIST);

         if(li != null && li.size()>=1)  {
             //todo: for now, we only handle the first exception out of the list - we just rethrow this
             //first exception.
             //in the end, we should enable the error handler to show all the exceptions at once
             boolean errorHandling = getBooleanValue(facesContext.getExternalContext().getInitParameter(ERROR_HANDLING_PARAMETER), true);

             if(errorHandling) {
                 String errorHandlerClass = facesContext.getExternalContext().getInitParameter(ERROR_HANDLER_PARAMETER);
                 if(errorHandlerClass != null) {
                     try {
                         Class clazz = Class.forName(errorHandlerClass);

                         Object errorHandler = clazz.newInstance();

                         Method m = clazz.getMethod("handleExceptionList", new Class[]{FacesContext.class,Exception.class});
                         m.invoke(errorHandler, new Object[]{facesContext, li});
                     }
                     catch(ClassNotFoundException ex) {
                         throw new ServletException("Error-Handler : " +errorHandlerClass+ " was not found. Fix your web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
                     } catch (IllegalAccessException ex) {
                         throw new ServletException("Constructor of error-Handler : " +errorHandlerClass+ " is not accessible. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
                     } catch (InstantiationException ex) {
                         throw new ServletException("Error-Handler : " +errorHandlerClass+ " could not be instantiated. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
                     } catch (NoSuchMethodException ex) {
                         //Handle in the old way, since no custom method handleExceptionList found,
                         //throwing the first FacesException on the list.
                         throw (FacesException) li.get(0);
                     } catch (InvocationTargetException ex) {
                         throw new ServletException("Excecution of method handleException in Error-Handler : " +errorHandlerClass+ " threw an exception. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
                     }
                 }
                 else {
                     _ErrorPageWriter.handleExceptionList(facesContext, li);
                 }
             }
             else {
                 _ErrorPageWriter.throwException((Exception) li.get(0));
             }
             return true;
         }
         return false;
     }

     private void handleLifecycleException(FacesContext facesContext, Exception e) throws IOException, ServletException {

         boolean errorHandling = getBooleanValue(facesContext.getExternalContext().getInitParameter(ERROR_HANDLING_PARAMETER), true);

         if(errorHandling) {
             String errorHandlerClass = facesContext.getExternalContext().getInitParameter(ERROR_HANDLER_PARAMETER);
             if(errorHandlerClass != null) {
                 try {
                     Class clazz = Class.forName(errorHandlerClass);

                     Object errorHandler = clazz.newInstance();

                     Method m = clazz.getMethod("handleException", new Class[]{FacesContext.class,Exception.class});
                     m.invoke(errorHandler, new Object[]{facesContext, e});
                 }
                 catch(ClassNotFoundException ex) {
                     throw new ServletException("Error-Handler : " +errorHandlerClass+ " was not found. Fix your web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
                 } catch (IllegalAccessException ex) {
                     throw new ServletException("Constructor of error-Handler : " +errorHandlerClass+ " is not accessible. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
                 } catch (InstantiationException ex) {
                     throw new ServletException("Error-Handler : " +errorHandlerClass+ " could not be instantiated. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
                 } catch (NoSuchMethodException ex) {
                     log.error("Error-Handler : " +errorHandlerClass+ " did not have a method with name : handleException and parameters : javax.faces.context.FacesContext, java.lang.Exception. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
                     //Try to look if it is implemented more general method handleThrowable
                     handleLifecycleThrowable(facesContext, e);
                 } catch (InvocationTargetException ex) {
                     throw new ServletException("Excecution of method handleException in Error-Handler : " +errorHandlerClass+ " threw an exception. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
                 }
             }
             else {
                 _ErrorPageWriter.handleException(facesContext, e);
             }
         }
         else {
             _ErrorPageWriter.throwException(e);
         }
     }

     private void handleLifecycleThrowable(FacesContext facesContext, Throwable e) throws IOException, ServletException {

         boolean errorHandling = getBooleanValue(facesContext.getExternalContext().getInitParameter(ERROR_HANDLING_PARAMETER), true);

         if(errorHandling) {
             String errorHandlerClass = facesContext.getExternalContext().getInitParameter(ERROR_HANDLER_PARAMETER);
             if(errorHandlerClass != null) {
                 try {
                     Class clazz = Class.forName(errorHandlerClass);

                     Object errorHandler = clazz.newInstance();

                     Method m = clazz.getMethod("handleThrowable", new Class[]{FacesContext.class,Throwable.class});
                     m.invoke(errorHandler, new Object[]{facesContext, e});
                 }
                 catch(ClassNotFoundException ex) {
                     throw new ServletException("Error-Handler : " +errorHandlerClass+ " was not found. Fix your web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
                 } catch (IllegalAccessException ex) {
                     throw new ServletException("Constructor of error-Handler : " +errorHandlerClass+ " is not accessible. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
                 } catch (InstantiationException ex) {
                     throw new ServletException("Error-Handler : " +errorHandlerClass+ " could not be instantiated. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
                 } catch (NoSuchMethodException ex) {
                     throw new ServletException("Error-Handler : " +errorHandlerClass+ " did not have a method with name : handleException and parameters : javax.faces.context.FacesContext, java.lang.Exception. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
                 } catch (InvocationTargetException ex) {
                     throw new ServletException("Excecution of method handleException in Error-Handler : " +errorHandlerClass+ " threw an exception. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
                 }
             }
             else {
                 _ErrorPageWriter.handleThrowable(facesContext, e);
             }
         }
         else {
             _ErrorPageWriter.throwException(e);
         }
     }

     private static boolean getBooleanValue(String initParameter, boolean defaultVal) {

         if(initParameter == null || initParameter.trim().length()==0)
             return defaultVal;

         return (initParameter.equalsIgnoreCase("on") || initParameter.equals("1") || initParameter.equalsIgnoreCase("true"));
     }

     private FacesContext prepareFacesContext(ServletRequest request, ServletResponse response) {
         FacesContext facesContext
                 = _facesContextFactory.getFacesContext(_servletConfig.getServletContext(),
                                                        request,
                                                        response,
                                                        _lifecycle);
         return facesContext;
     }
 }
	/*
	* 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 javax.faces.webapp;

	import java.io.IOException;
	import java.lang.reflect.Method;
	import java.lang.reflect.InvocationTargetException;
	import java.util.List;

	import javax.faces.FactoryFinder;
	import javax.faces.FacesException;
	import javax.faces.context.FacesContext;
	import javax.faces.context.FacesContextFactory;
	import javax.faces.lifecycle.Lifecycle;
	import javax.faces.lifecycle.LifecycleFactory;
	import javax.servlet.Servlet;
	import javax.servlet.ServletConfig;
	import javax.servlet.ServletException;
	import javax.servlet.ServletRequest;
	import javax.servlet.ServletResponse;
	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletResponse;

	import org.apache.commons.logging.Log;
	import org.apache.commons.logging.LogFactory;

	/**
	* see Javadoc of <a href="http://java.sun.com/j2ee/javaserverfaces/1.1_01/docs/api/index.html">JSF Specification</a>
	*
	* @author Manfred Geiler (latest modification by $Author$)
	* @version $Revision$ $Date$
	*/
	public final class FacesServlet
	implements Servlet
	{
	private static final Log log = LogFactory.getLog(FacesServlet.class);
	public static final String CONFIG_FILES_ATTR = "javax.faces.CONFIG_FILES";
	public static final String LIFECYCLE_ID_ATTR = "javax.faces.LIFECYCLE_ID";

	private static final String SERVLET_INFO = "FacesServlet of the MyFaces API implementation";
	private static final String ERROR_HANDLING_PARAMETER = "org.apache.myfaces.ERROR_HANDLING";
	private static final String ERROR_HANDLER_PARAMETER = "org.apache.myfaces.ERROR_HANDLER";
	private static final String ERROR_HANDLING_EXCEPTION_LIST = "org.apache.myfaces.errorHandling.exceptionList";

	private ServletConfig _servletConfig;
	private FacesContextFactory _facesContextFactory;
	private Lifecycle _lifecycle;

	public FacesServlet()
	{
	super();
	}

	public void destroy()
	{
	_servletConfig = null;
	_facesContextFactory = null;
	_lifecycle = null;
	if(log.isTraceEnabled()) log.trace("destroy");
	}

	public ServletConfig getServletConfig()
	{
	return _servletConfig;
	}

	public String getServletInfo()
	{
	return SERVLET_INFO;
	}

	private String getLifecycleId()
	{
	String lifecycleId = _servletConfig.getServletContext().getInitParameter(LIFECYCLE_ID_ATTR);
	return lifecycleId != null ? lifecycleId : LifecycleFactory.DEFAULT_LIFECYCLE;
	}

	public void init(ServletConfig servletConfig)
	throws ServletException
	{
	if(log.isTraceEnabled()) log.trace("init begin");
	_servletConfig = servletConfig;
	_facesContextFactory = (FacesContextFactory)FactoryFinder.getFactory(FactoryFinder.FACES_CONTEXT_FACTORY);
	//TODO: null-check for Weblogic, that tries to initialize Servlet before ContextListener

	//Javadoc says: Lifecycle instance is shared across multiple simultaneous requests, it must be implemented in a thread-safe manner.
	//So we can acquire it here once:
	LifecycleFactory lifecycleFactory = (LifecycleFactory)FactoryFinder.getFactory(FactoryFinder.LIFECYCLE_FACTORY);
	_lifecycle = lifecycleFactory.getLifecycle(getLifecycleId());
	if(log.isTraceEnabled()) log.trace("init end");
	}

	public void service(ServletRequest request,
	ServletResponse response)
	throws IOException,
	ServletException
	{

	HttpServletRequest httpRequest = ((HttpServletRequest) request);
	String pathInfo = httpRequest.getPathInfo();

	// if it is a prefix mapping ...
	if (pathInfo != null
	&& (pathInfo.startsWith("/WEB-INF") \|\| pathInfo
	.startsWith("/META-INF")))
	{
	StringBuffer buffer = new StringBuffer();

	buffer.append(" Someone is trying to access a secure resource : ").append(pathInfo);
	buffer.append("\n remote address is ").append(httpRequest.getRemoteAddr());
	buffer.append("\n remote host is ").append(httpRequest.getRemoteHost());
	buffer.append("\n remote user is ").append(httpRequest.getRemoteUser());
	buffer.append("\n request URI is ").append(httpRequest.getRequestURI());

	log.warn(buffer.toString());

	// Why does RI return a 404 and not a 403, SC_FORBIDDEN ?

	((HttpServletResponse) response)
	.sendError(HttpServletResponse.SC_NOT_FOUND);
	return;
	}

	if(log.isTraceEnabled()) log.trace("service begin");
	FacesContext facesContext = prepareFacesContext(request, response);
	try {
	_lifecycle.execute(facesContext);

	if (!handleQueuedExceptions(facesContext))
	{
	_lifecycle.render(facesContext);
	}
	}
	catch (Exception e)
	{
	handleLifecycleException(facesContext, e);
	}
	catch (Throwable e)
	{
	handleLifecycleThrowable(facesContext, e);
	}
	finally
	{
	facesContext.release();
	}
	if(log.isTraceEnabled()) log.trace("service end");
	}

	/**This method makes sure we see an exception page also
	* if an exception has been thrown in UIInput.updateModel();
	* In this method, according to the spec, we may not rethrow the
	* exception, so we add it to a list and process it here.
	*
	* Attention: if you use redirects, the exceptions will get lost - exactly
	* like in the case of FacesMessages. If you want them to be taken over to the
	* next request, you should try the redirect-tracker of MyFaces.
	*
	* @param facesContext
	* @throws javax.faces.FacesException
	*/
	private boolean handleQueuedExceptions(FacesContext facesContext) throws IOException, ServletException {
	List li = (List)
	facesContext.getExternalContext().getRequestMap().get(ERROR_HANDLING_EXCEPTION_LIST);

	if(li != null && li.size()>=1) {
	//todo: for now, we only handle the first exception out of the list - we just rethrow this
	//first exception.
	//in the end, we should enable the error handler to show all the exceptions at once
	boolean errorHandling = getBooleanValue(facesContext.getExternalContext().getInitParameter(ERROR_HANDLING_PARAMETER), true);

	if(errorHandling) {
	String errorHandlerClass = facesContext.getExternalContext().getInitParameter(ERROR_HANDLER_PARAMETER);
	if(errorHandlerClass != null) {
	try {
	Class clazz = Class.forName(errorHandlerClass);

	Object errorHandler = clazz.newInstance();

	Method m = clazz.getMethod("handleExceptionList", new Class[]{FacesContext.class,Exception.class});
	m.invoke(errorHandler, new Object[]{facesContext, li});
	}
	catch(ClassNotFoundException ex) {
	throw new ServletException("Error-Handler : " +errorHandlerClass+ " was not found. Fix your web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
	} catch (IllegalAccessException ex) {
	throw new ServletException("Constructor of error-Handler : " +errorHandlerClass+ " is not accessible. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
	} catch (InstantiationException ex) {
	throw new ServletException("Error-Handler : " +errorHandlerClass+ " could not be instantiated. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
	} catch (NoSuchMethodException ex) {
	//Handle in the old way, since no custom method handleExceptionList found,
	//throwing the first FacesException on the list.
	throw (FacesException) li.get(0);
	} catch (InvocationTargetException ex) {
	throw new ServletException("Excecution of method handleException in Error-Handler : " +errorHandlerClass+ " threw an exception. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
	}
	}
	else {
	_ErrorPageWriter.handleExceptionList(facesContext, li);
	}
	}
	else {
	_ErrorPageWriter.throwException((Exception) li.get(0));
	}
	return true;
	}
	return false;
	}

	private void handleLifecycleException(FacesContext facesContext, Exception e) throws IOException, ServletException {

	boolean errorHandling = getBooleanValue(facesContext.getExternalContext().getInitParameter(ERROR_HANDLING_PARAMETER), true);

	if(errorHandling) {
	String errorHandlerClass = facesContext.getExternalContext().getInitParameter(ERROR_HANDLER_PARAMETER);
	if(errorHandlerClass != null) {
	try {
	Class clazz = Class.forName(errorHandlerClass);

	Object errorHandler = clazz.newInstance();

	Method m = clazz.getMethod("handleException", new Class[]{FacesContext.class,Exception.class});
	m.invoke(errorHandler, new Object[]{facesContext, e});
	}
	catch(ClassNotFoundException ex) {
	throw new ServletException("Error-Handler : " +errorHandlerClass+ " was not found. Fix your web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
	} catch (IllegalAccessException ex) {
	throw new ServletException("Constructor of error-Handler : " +errorHandlerClass+ " is not accessible. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
	} catch (InstantiationException ex) {
	throw new ServletException("Error-Handler : " +errorHandlerClass+ " could not be instantiated. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
	} catch (NoSuchMethodException ex) {
	log.error("Error-Handler : " +errorHandlerClass+ " did not have a method with name : handleException and parameters : javax.faces.context.FacesContext, java.lang.Exception. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
	//Try to look if it is implemented more general method handleThrowable
	handleLifecycleThrowable(facesContext, e);
	} catch (InvocationTargetException ex) {
	throw new ServletException("Excecution of method handleException in Error-Handler : " +errorHandlerClass+ " threw an exception. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
	}
	}
	else {
	_ErrorPageWriter.handleException(facesContext, e);
	}
	}
	else {
	_ErrorPageWriter.throwException(e);
	}
	}

	private void handleLifecycleThrowable(FacesContext facesContext, Throwable e) throws IOException, ServletException {

	boolean errorHandling = getBooleanValue(facesContext.getExternalContext().getInitParameter(ERROR_HANDLING_PARAMETER), true);

	if(errorHandling) {
	String errorHandlerClass = facesContext.getExternalContext().getInitParameter(ERROR_HANDLER_PARAMETER);
	if(errorHandlerClass != null) {
	try {
	Class clazz = Class.forName(errorHandlerClass);

	Object errorHandler = clazz.newInstance();

	Method m = clazz.getMethod("handleThrowable", new Class[]{FacesContext.class,Throwable.class});
	m.invoke(errorHandler, new Object[]{facesContext, e});
	}
	catch(ClassNotFoundException ex) {
	throw new ServletException("Error-Handler : " +errorHandlerClass+ " was not found. Fix your web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
	} catch (IllegalAccessException ex) {
	throw new ServletException("Constructor of error-Handler : " +errorHandlerClass+ " is not accessible. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
	} catch (InstantiationException ex) {
	throw new ServletException("Error-Handler : " +errorHandlerClass+ " could not be instantiated. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
	} catch (NoSuchMethodException ex) {
	throw new ServletException("Error-Handler : " +errorHandlerClass+ " did not have a method with name : handleException and parameters : javax.faces.context.FacesContext, java.lang.Exception. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
	} catch (InvocationTargetException ex) {
	throw new ServletException("Excecution of method handleException in Error-Handler : " +errorHandlerClass+ " threw an exception. Error-Handler is specified in web.xml-parameter : "+ERROR_HANDLER_PARAMETER,ex);
	}
	}
	else {
	_ErrorPageWriter.handleThrowable(facesContext, e);
	}
	}
	else {
	_ErrorPageWriter.throwException(e);
	}
	}

	private static boolean getBooleanValue(String initParameter, boolean defaultVal) {

	if(initParameter == null \|\| initParameter.trim().length()==0)
	return defaultVal;

	return (initParameter.equalsIgnoreCase("on") \|\| initParameter.equals("1") \|\| initParameter.equalsIgnoreCase("true"));
	}

	private FacesContext prepareFacesContext(ServletRequest request, ServletResponse response) {
	FacesContext facesContext
	= _facesContextFactory.getFacesContext(_servletConfig.getServletContext(),
	request,
	response,
	_lifecycle);
	return facesContext;
	}
	}