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The private implementation classes of the Apache MyFaces Core JSF-2.0 Implementation
/*
* 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.lifecycle;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.faces.FacesException;
import javax.faces.application.ProjectStage;
import javax.faces.context.FacesContext;
import javax.faces.context.Flash;
import javax.faces.event.ExceptionQueuedEvent;
import javax.faces.event.ExceptionQueuedEventContext;
import javax.faces.event.PhaseId;
import javax.faces.event.PhaseListener;
import javax.faces.lifecycle.Lifecycle;
import org.apache.myfaces.config.FacesConfigurator;
import org.apache.myfaces.renderkit.ErrorPageWriter;
import org.apache.myfaces.shared.util.ClassUtils;
import org.apache.myfaces.shared_impl.webapp.webxml.WebXml;
import org.apache.myfaces.util.DebugUtils;
/**
* Implements the lifecycle as described in Spec. 1.0 PFD Chapter 2
*
* @author Manfred Geiler (latest modification by $Author: lu4242 $)
* @author Nikolay Petrov
* @version $Revision: 1151677 $ $Date: 2011-07-27 19:03:59 -0500 (Wed, 27 Jul 2011) $
*/
public class LifecycleImpl extends Lifecycle
{
//private static final Log log = LogFactory.getLog(LifecycleImpl.class);
private static final Logger log = Logger.getLogger(LifecycleImpl.class.getName());
/**
* Boolean.TRUE is stored under this key in the application map if
* the first request has been processed.
*/
public static final String FIRST_REQUEST_PROCESSED_PARAM = "org.apache.myfaces.lifecycle.first.request.processed";
private final PhaseExecutor[] lifecycleExecutors;
private final PhaseExecutor renderExecutor;
/**
* Initially, for ensure thread safety we used synchronization blocks and a cached
* _phaseListenerArray and that works. The intention is ensure atomicity between
* _phaseListenerList and _phaseListenerArray, but thinking more about it use
* CopyOnWriteArrayList and do not use _phaseListenerArray is a lot better.
*
* Most times, we have few instances of PhaseListener registered, so the advantage of
* use _phaseListenerArray is overcome by do not have a synchronization block on getPhaseListeners().
* Additionally, it is more often to perform traversals than insertions/removals and
* we can expect only 2 calls for getPhaseListeners() per request (so only two copy
* operations of a very small list).
*/
private final List _phaseListenerList = new CopyOnWriteArrayList(); // new ArrayList();
/**
* This variable should be marked as volatile to ensure all threads can see it
* after the first request is processed. Note that LifecycleImpl instance could be
* shared by multiple requests at the same time, so this is relevant to prevent
* multiple updates to FIRST_REQUEST_PROCESSED_PARAM. Really since the value
* only changes from false to true, have a racy single check here does not harm, but
* note in this case the semantic of the variable must be preserved.
*/
private volatile boolean _firstRequestProcessed = false;
/**
* Lazy cache for returning _phaseListenerList as an Array.
*
* Replaced by _phaseListenerList CopyOnWriteArrayList
*/
//private PhaseListener[] _phaseListenerArray = null;
public LifecycleImpl()
{
// hide from public access
lifecycleExecutors = new PhaseExecutor[] { new RestoreViewExecutor(), new ApplyRequestValuesExecutor(),
new ProcessValidationsExecutor(), new UpdateModelValuesExecutor(), new InvokeApplicationExecutor() };
renderExecutor = new RenderResponseExecutor();
}
@Override
public void execute(FacesContext facesContext) throws FacesException
{
//try
//{
// check for updates of web.xml and faces-config descriptors
// only if project state is not production
if(!facesContext.isProjectStage(ProjectStage.Production))
{
WebXml.update(facesContext.getExternalContext());
new FacesConfigurator(facesContext.getExternalContext()).update();
}
PhaseListenerManager phaseListenerMgr = new PhaseListenerManager(this, facesContext, getPhaseListeners());
for (PhaseExecutor executor : lifecycleExecutors)
{
if (executePhase(facesContext, executor, phaseListenerMgr))
{
return;
}
}
//}
//catch (Throwable ex)
//{
// handle the Throwable accordingly. Maybe generate an error page.
//ErrorPageWriter.handleThrowable(facesContext, ex);
//}
}
private boolean executePhase(FacesContext context, PhaseExecutor executor, PhaseListenerManager phaseListenerMgr)
throws FacesException
{
boolean skipFurtherProcessing = false;
if (log.isLoggable(Level.FINEST))
{
log.finest("entering " + executor.getPhase() + " in " + LifecycleImpl.class.getName());
}
PhaseId currentPhaseId = executor.getPhase();
Flash flash = context.getExternalContext().getFlash();
try
{
/*
* Specification, section 2.2
* The default request lifecycle processing implementation must ensure that the currentPhaseId property
* of the FacesContext instance for this request is set with the proper PhaseId constant for the current
* phase as the first instruction at the beginning of each phase
*/
context.setCurrentPhaseId(currentPhaseId);
flash.doPrePhaseActions(context);
// let the PhaseExecutor do some pre-phase actions
executor.doPrePhaseActions(context);
phaseListenerMgr.informPhaseListenersBefore(currentPhaseId);
if (isResponseComplete(context, currentPhaseId, true))
{
// have to return right away
return true;
}
if (shouldRenderResponse(context, currentPhaseId, true))
{
skipFurtherProcessing = true;
}
if (executor.execute(context))
{
return true;
}
}
catch (Throwable e) {
// JSF 2.0: publish the executor's exception (if any).
publishException (e, currentPhaseId, context);
}
finally
{
phaseListenerMgr.informPhaseListenersAfter(currentPhaseId);
flash.doPostPhaseActions(context);
}
context.getExceptionHandler().handle();
if (isResponseComplete(context, currentPhaseId, false) || shouldRenderResponse(context, currentPhaseId, false))
{
// since this phase is completed we don't need to return right away even if the response is completed
skipFurtherProcessing = true;
}
if (!skipFurtherProcessing && log.isLoggable(Level.FINEST))
{
log.finest("exiting " + executor.getPhase() + " in " + LifecycleImpl.class.getName());
}
return skipFurtherProcessing;
}
@Override
public void render(FacesContext facesContext) throws FacesException
{
//try
//{
// if the response is complete we should not be invoking the phase listeners
if (isResponseComplete(facesContext, renderExecutor.getPhase(), true))
{
return;
}
if (log.isLoggable(Level.FINEST))
log.finest("entering " + renderExecutor.getPhase() + " in " + LifecycleImpl.class.getName());
PhaseListenerManager phaseListenerMgr = new PhaseListenerManager(this, facesContext, getPhaseListeners());
Flash flash = facesContext.getExternalContext().getFlash();
try
{
facesContext.setCurrentPhaseId(renderExecutor.getPhase());
flash.doPrePhaseActions(facesContext);
// let the PhaseExecutor do some pre-phase actions
renderExecutor.doPrePhaseActions(facesContext);
phaseListenerMgr.informPhaseListenersBefore(renderExecutor.getPhase());
// also possible that one of the listeners completed the response
if (isResponseComplete(facesContext, renderExecutor.getPhase(), true))
{
return;
}
renderExecutor.execute(facesContext);
}
catch (Throwable e) {
// JSF 2.0: publish the executor's exception (if any).
publishException (e, renderExecutor.getPhase(), facesContext);
}
finally
{
phaseListenerMgr.informPhaseListenersAfter(renderExecutor.getPhase());
flash.doPostPhaseActions(facesContext);
// publish a field in the application map to indicate
// that the first request has been processed
requestProcessed(facesContext);
}
facesContext.getExceptionHandler().handle();
if (log.isLoggable(Level.FINEST))
{
// Note: DebugUtils Logger must also be in trace level
DebugUtils.traceView("View after rendering");
}
if (log.isLoggable(Level.FINEST))
{
log.finest("exiting " + renderExecutor.getPhase() + " in " + LifecycleImpl.class.getName());
}
//}
//catch (Throwable ex)
//{
// handle the Throwable accordingly. Maybe generate an error page.
//ErrorPageWriter.handleThrowable(facesContext, ex);
//}
}
private boolean isResponseComplete(FacesContext facesContext, PhaseId phase, boolean before)
{
boolean flag = false;
if (facesContext.getResponseComplete())
{
if (log.isLoggable(Level.FINE))
{
log.fine("exiting from lifecycle.execute in " + phase
+ " because getResponseComplete is true from one of the " + (before ? "before" : "after")
+ " listeners");
}
flag = true;
}
return flag;
}
private boolean shouldRenderResponse(FacesContext facesContext, PhaseId phase, boolean before)
{
boolean flag = false;
if (facesContext.getRenderResponse())
{
if (log.isLoggable(Level.FINE))
{
log.fine("exiting from lifecycle.execute in " + phase
+ " because getRenderResponse is true from one of the " + (before ? "before" : "after")
+ " listeners");
}
flag = true;
}
return flag;
}
@Override
public void addPhaseListener(PhaseListener phaseListener)
{
if (phaseListener == null)
{
throw new NullPointerException("PhaseListener must not be null.");
}
//synchronized (_phaseListenerList)
//{
_phaseListenerList.add(phaseListener);
//_phaseListenerArray = null; // reset lazy cache array
//}
}
@Override
public void removePhaseListener(PhaseListener phaseListener)
{
if (phaseListener == null)
{
throw new NullPointerException("PhaseListener must not be null.");
}
//synchronized (_phaseListenerList)
//{
_phaseListenerList.remove(phaseListener);
//_phaseListenerArray = null; // reset lazy cache array
//}
}
@Override
public PhaseListener[] getPhaseListeners()
{
//synchronized (_phaseListenerList)
//{
// (re)build lazy cache array if necessary
//if (_phaseListenerArray == null)
//{
// _phaseListenerArray = _phaseListenerList.toArray(new PhaseListener[_phaseListenerList.size()]);
//}
//return _phaseListenerArray;
//}
return _phaseListenerList.toArray(new PhaseListener[_phaseListenerList.size()]);
}
private void publishException (Throwable e, PhaseId phaseId, FacesContext facesContext)
{
ExceptionQueuedEventContext context = new ExceptionQueuedEventContext (facesContext, e, null, phaseId);
facesContext.getApplication().publishEvent (facesContext, ExceptionQueuedEvent.class, context);
}
/**
* This method places an attribute on the application map to
* indicate that the first request has been processed. This
* attribute is used by several methods in ApplicationImpl
* to determine whether or not to throw an IllegalStateException
* @param facesContext
*/
private void requestProcessed(FacesContext facesContext)
{
if(!_firstRequestProcessed)
{
// The order here is important. First it is necessary to put
// the value on application map before change the value here.
// If multiple threads reach this point concurrently, the
// variable will be written on the application map at the same
// time but always with the same value.
facesContext.getExternalContext().getApplicationMap()
.put(FIRST_REQUEST_PROCESSED_PARAM, Boolean.TRUE);
_firstRequestProcessed = true;
}
}
}