/*
* Copyright 2004 The Apache Software Foundation.
*
* Licensed 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.application.jsp;
import org.apache.commons.collections.map.AbstractReferenceMap;
import org.apache.commons.collections.map.ReferenceMap;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.myfaces.application.MyfacesStateManager;
import org.apache.myfaces.application.TreeStructureManager;
import org.apache.myfaces.renderkit.MyfacesResponseStateManager;
import org.apache.myfaces.shared_impl.renderkit.RendererUtils;
import org.apache.myfaces.shared_impl.util.MyFacesObjectInputStream;
import javax.faces.FactoryFinder;
import javax.faces.component.NamingContainer;
import javax.faces.component.UIComponent;
import javax.faces.component.UIViewRoot;
import javax.faces.context.ExternalContext;
import javax.faces.context.FacesContext;
import javax.faces.render.RenderKit;
import javax.faces.render.RenderKitFactory;
import javax.faces.render.ResponseStateManager;
import java.io.*;
import java.lang.reflect.Method;
import java.util.*;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
/**
* Default StateManager implementation for use when views are defined
* via tags in JSP pages.
*
* @author Thomas Spiegl (latest modification by $Author: bommel $)
* @author Manfred Geiler
* @version $Revision: 650105 $ $Date: 2008-04-21 06:28:16 -0500 (Mon, 21 Apr 2008) $
*/
public class JspStateManagerImpl
extends MyfacesStateManager
{
private static final Log log = LogFactory.getLog(JspStateManagerImpl.class);
private static final String SERIALIZED_VIEW_SESSION_ATTR
= JspStateManagerImpl.class.getName() + ".SERIALIZED_VIEW";
private static final String SERIALIZED_VIEW_REQUEST_ATTR
= JspStateManagerImpl.class.getName() + ".SERIALIZED_VIEW";
private static final String RESTORED_SERIALIZED_VIEW_REQUEST_ATTR
= JspStateManagerImpl.class.getName() + ".RESTORED_SERIALIZED_VIEW";
/**
* Only applicable if state saving method is "server" (= default).
* Defines the amount (default = 20) of the latest views are stored in session.
*/
private static final String NUMBER_OF_VIEWS_IN_SESSION_PARAM = "org.apache.myfaces.NUMBER_OF_VIEWS_IN_SESSION";
/**
* Default value for <code>org.apache.myfaces.NUMBER_OF_VIEWS_IN_SESSION</code> context parameter.
*/
private static final int DEFAULT_NUMBER_OF_VIEWS_IN_SESSION = 20;
/**
* Only applicable if state saving method is "server" (= default).
* If <code>true</code> (default) the state will be serialized to a byte stream before it is written to the session.
* If <code>false</code> the state will not be serialized to a byte stream.
*/
private static final String SERIALIZE_STATE_IN_SESSION_PARAM = "org.apache.myfaces.SERIALIZE_STATE_IN_SESSION";
/**
* Only applicable if state saving method is "server" (= default) and if <code>org.apache.myfaces.SERIALIZE_STATE_IN_SESSION</code> is <code>true</code> (= default).
* If <code>true</code> (default) the serialized state will be compressed before it is written to the session.
* If <code>false</code> the state will not be compressed.
*/
private static final String COMPRESS_SERVER_STATE_PARAM = "org.apache.myfaces.COMPRESS_STATE_IN_SESSION";
/**
* Default value for <code>org.apache.myfaces.COMPRESS_STATE_IN_SESSION</code> context parameter.
*/
private static final boolean DEFAULT_COMPRESS_SERVER_STATE_PARAM = true;
/**
* Default value for <code>org.apache.myfaces.SERIALIZE_STATE_IN_SESSION</code> context parameter.
*/
private static final boolean DEFAULT_SERIALIZE_STATE_IN_SESSION = true;
private static final int UNCOMPRESSED_FLAG = 0;
private static final int COMPRESSED_FLAG = 1;
private static final int JSF_SEQUENCE_INDEX = 0;
private RenderKitFactory _renderKitFactory = null;
public JspStateManagerImpl()
{
if (log.isTraceEnabled()) log.trace("New JspStateManagerImpl instance created");
}
protected Object getComponentStateToSave(FacesContext facesContext)
{
if (log.isTraceEnabled()) log.trace("Entering getComponentStateToSave");
UIViewRoot viewRoot = facesContext.getViewRoot();
if (viewRoot.isTransient())
{
return null;
}
Object serializedComponentStates = viewRoot.processSaveState(facesContext);
//Locale is a state attribute of UIViewRoot and need not be saved explicitly
if (log.isTraceEnabled()) log.trace("Exiting getComponentStateToSave");
return serializedComponentStates;
}
/**
* Return an object which contains info about the UIComponent type
* of each node in the view tree. This allows an identical UIComponent
* tree to be recreated later, though all the components will have
* just default values for their members.
*/
protected Object getTreeStructureToSave(FacesContext facesContext)
{
if (log.isTraceEnabled()) log.trace("Entering getTreeStructureToSave");
UIViewRoot viewRoot = facesContext.getViewRoot();
if (viewRoot.isTransient())
{
return null;
}
TreeStructureManager tsm = new TreeStructureManager();
Object retVal = tsm.buildTreeStructureToSave(viewRoot);
if (log.isTraceEnabled()) log.trace("Exiting getTreeStructureToSave");
return retVal;
}
/**
* Given a tree of UIComponent objects created the default constructor
* for each node, retrieve saved state info (from either the client or
* the server) and walk the tree restoring the members of each node
* from the saved state information.
*/
protected void restoreComponentState(FacesContext facesContext,
UIViewRoot uiViewRoot,
String renderKitId)
{
if (log.isTraceEnabled()) log.trace("Entering restoreComponentState");
//===========================================
// first, locate the saved state information
//===========================================
RenderKit renderKit = getRenderKitFactory().getRenderKit(facesContext, renderKitId);
ResponseStateManager responseStateManager = renderKit.getResponseStateManager();
Object serializedComponentStates;
if (isSavingStateInClient(facesContext))
{
if (isLegacyResponseStateManager(responseStateManager))
{
serializedComponentStates = responseStateManager.getComponentStateToRestore(facesContext);
}
else
{
serializedComponentStates = responseStateManager.getState(facesContext, uiViewRoot.getViewId());
}
if (serializedComponentStates == null)
{
log.error("No serialized component state found in client request!");
// mark UIViewRoot invalid by resetting view id
uiViewRoot.setViewId(null);
return;
}
}
else
{
Integer serverStateId = getServerStateId((Object[]) responseStateManager.getState(facesContext, uiViewRoot.getViewId()));
Object[] stateObj = (Object[]) getSerializedViewFromServletSession(facesContext, uiViewRoot.getViewId(), serverStateId);
if (stateObj == null)
{
log.error("No serialized view found in server session!");
// mark UIViewRoot invalid by resetting view id
uiViewRoot.setViewId(null);
return;
}
SerializedView serializedView = new SerializedView(stateObj[0], stateObj[1]);
serializedComponentStates = serializedView.getState();
if (serializedComponentStates == null)
{
log.error("No serialized component state found in server session!");
return;
}
}
if (uiViewRoot.getRenderKitId() == null)
{
//Just to be sure...
uiViewRoot.setRenderKitId(renderKitId);
}
// now ask the view root component to restore its state
uiViewRoot.processRestoreState(facesContext, serializedComponentStates);
if (log.isTraceEnabled()) log.trace("Exiting restoreComponentState");
}
protected Integer getServerStateId(Object[] state)
{
if (state != null)
{
Object serverStateId = state[JSF_SEQUENCE_INDEX];
if (serverStateId != null)
{
return Integer.valueOf((String) serverStateId, Character.MAX_RADIX);
}
}
return null;
}
/**
* See getTreeStructureToSave.
*/
protected UIViewRoot restoreTreeStructure(FacesContext facesContext,
String viewId,
String renderKitId)
{
if (log.isTraceEnabled()) log.trace("Entering restoreTreeStructure");
RenderKit rk = getRenderKitFactory().getRenderKit(facesContext, renderKitId);
ResponseStateManager responseStateManager = rk.getResponseStateManager();
UIViewRoot uiViewRoot;
if (isSavingStateInClient(facesContext))
{
//reconstruct tree structure from request
Object treeStructure = responseStateManager.getTreeStructureToRestore(facesContext, viewId);
if (treeStructure == null)
{
if (log.isDebugEnabled()) log.debug("Exiting restoreTreeStructure - No tree structure state found in client request");
return null;
}
TreeStructureManager tsm = new TreeStructureManager();
uiViewRoot = tsm.restoreTreeStructure(treeStructure);
if (log.isTraceEnabled()) log.trace("Tree structure restored from client request");
}
else
{
//reconstruct tree structure from ServletSession
Integer serverStateId = getServerStateId((Object[]) responseStateManager.getState(facesContext, viewId));
Object[] stateObj = (Object[]) getSerializedViewFromServletSession(facesContext, viewId, serverStateId);
if (stateObj == null)
{
if (log.isDebugEnabled()) log.debug("Exiting restoreTreeStructure - No serialized view found in server session!");
return null;
}
SerializedView serializedView = new SerializedView(stateObj[0], stateObj[1]);
Object treeStructure = serializedView.getStructure();
if (treeStructure == null)
{
if (log.isDebugEnabled()) log.debug("Exiting restoreTreeStructure - No tree structure state found in server session, former UIViewRoot must have been transient");
return null;
}
TreeStructureManager tsm = new TreeStructureManager();
uiViewRoot = tsm.restoreTreeStructure(serializedView.getStructure());
if (log.isTraceEnabled()) log.trace("Tree structure restored from server session");
}
if (log.isTraceEnabled()) log.trace("Exiting restoreTreeStructure");
return uiViewRoot;
}
public UIViewRoot restoreView(FacesContext facesContext, String viewId, String renderKitId)
{
if (log.isTraceEnabled()) log.trace("Entering restoreView - viewId: "+viewId+" ; renderKitId: "+renderKitId);
RenderKit renderKit = getRenderKitFactory().getRenderKit(facesContext, renderKitId);
ResponseStateManager responseStateManager = renderKit.getResponseStateManager();
Object state;
if (isSavingStateInClient(facesContext))
{
if (log.isTraceEnabled()) log.trace("Restoring view from client");
state = responseStateManager.getState(facesContext, viewId);
}
else
{
if (log.isTraceEnabled()) log.trace("Restoring view from session");
Integer serverStateId = getServerStateId((Object[]) responseStateManager.getState(facesContext, viewId));
state = getSerializedViewFromServletSession(facesContext, viewId, serverStateId);
}
UIViewRoot uiViewRoot = null;
if (state != null) {
Object[] stateArray = (Object[])state;
TreeStructureManager tsm = new TreeStructureManager();
uiViewRoot = tsm.restoreTreeStructure(stateArray[0]);
if (uiViewRoot != null) {
uiViewRoot.processRestoreState(facesContext, stateArray[1]);
}
}
if (log.isTraceEnabled()) log.trace("Exiting restoreView - "+viewId);
return uiViewRoot;
}
public SerializedView saveSerializedView(FacesContext facesContext) throws IllegalStateException
{
if (log.isTraceEnabled()) log.trace("Entering saveSerializedView");
checkForDuplicateIds(facesContext, facesContext.getViewRoot(), new HashSet<String>());
if (log.isTraceEnabled()) log.trace("Processing saveSerializedView - Checked for duplicate Ids");
ExternalContext externalContext = facesContext.getExternalContext();
// SerializedView already created before within this request?
Object serializedView = externalContext.getRequestMap()
.get(SERIALIZED_VIEW_REQUEST_ATTR);
if (serializedView == null)
{
if (log.isTraceEnabled()) log.trace("Processing saveSerializedView - create new serialized view");
// first call to saveSerializedView --> create SerializedView
Object treeStruct = getTreeStructureToSave(facesContext);
Object compStates = getComponentStateToSave(facesContext);
serializedView = new Object[] {treeStruct, compStates};
externalContext.getRequestMap().put(SERIALIZED_VIEW_REQUEST_ATTR,
serializedView);
if (log.isTraceEnabled()) log.trace("Processing saveSerializedView - new serialized view created");
}
Object[] serializedViewArray = (Object[]) serializedView;
if (!isSavingStateInClient(facesContext))
{
if (log.isTraceEnabled()) log.trace("Processing saveSerializedView - server-side state saving - save state");
//save state in server session
saveSerializedViewInServletSession(facesContext, serializedView);
if (log.isTraceEnabled()) log.trace("Exiting saveSerializedView - server-side state saving - saved state");
return new SerializedView(serializedViewArray[0], new Object[0]);
}
if (log.isTraceEnabled()) log.trace("Exiting saveSerializedView - client-side state saving");
return new SerializedView(serializedViewArray[0], serializedViewArray[1]);
}
private static void checkForDuplicateIds(FacesContext context,
UIComponent component,
Set<String> ids)
{
String id = component.getId();
if (id != null && !ids.add(id))
{
throw new IllegalStateException("Client-id : "+id +
" is duplicated in the faces tree. Component : "+component.getClientId(context)+", path: "+
getPathToComponent(component));
}
if (component instanceof NamingContainer)
{
ids = new HashSet<String>();
}
Iterator it = component.getFacetsAndChildren();
while (it.hasNext())
{
UIComponent kid = (UIComponent) it.next();
checkForDuplicateIds(context, kid, ids);
}
}
private static String getPathToComponent(UIComponent component)
{
StringBuffer buf = new StringBuffer();
if(component == null)
{
buf.append("{Component-Path : ");
buf.append("[null]}");
return buf.toString();
}
getPathToComponent(component,buf);
buf.insert(0,"{Component-Path : ");
buf.append("}");
return buf.toString();
}
private static void getPathToComponent(UIComponent component, StringBuffer buf)
{
if(component == null)
return;
StringBuffer intBuf = new StringBuffer();
intBuf.append("[Class: ");
intBuf.append(component.getClass().getName());
if(component instanceof UIViewRoot)
{
intBuf.append(",ViewId: ");
intBuf.append(((UIViewRoot) component).getViewId());
}
else
{
intBuf.append(",Id: ");
intBuf.append(component.getId());
}
intBuf.append("]");
buf.insert(0,intBuf.toString());
if(component!=null)
{
getPathToComponent(component.getParent(),buf);
}
}
public void writeState(FacesContext facesContext,
SerializedView serializedView) throws IOException
{
if (log.isTraceEnabled()) log.trace("Entering writeState");
UIViewRoot uiViewRoot = facesContext.getViewRoot();
//save state in response (client)
RenderKit renderKit = getRenderKitFactory().getRenderKit(facesContext, uiViewRoot.getRenderKitId());
ResponseStateManager responseStateManager = renderKit.getResponseStateManager();
if (isLegacyResponseStateManager(responseStateManager))
{
responseStateManager.writeState(facesContext, serializedView);
}
else if (!isSavingStateInClient(facesContext))
{
Object[] state = new Object[2];
state[JSF_SEQUENCE_INDEX] = Integer.toString(getNextViewSequence(facesContext), Character.MAX_RADIX);
responseStateManager.writeState(facesContext, state);
}
else
{
Object[] state = new Object[2];
state[0] = serializedView.getStructure();
state[1] = serializedView.getState();
responseStateManager.writeState(facesContext, state);
}
if (log.isTraceEnabled()) log.trace("Exiting writeState");
}
/**
* MyFaces extension
* @param facesContext
* @param serializedView
* @throws IOException
*/
public void writeStateAsUrlParams(FacesContext facesContext,
SerializedView serializedView) throws IOException
{
if (log.isTraceEnabled()) log.trace("Entering writeStateAsUrlParams");
if (isSavingStateInClient(facesContext))
{
if (log.isTraceEnabled()) log.trace("Processing writeStateAsUrlParams - client-side state saving writing state");
UIViewRoot uiViewRoot = facesContext.getViewRoot();
//save state in response (client)
RenderKit renderKit = getRenderKitFactory().getRenderKit(facesContext, uiViewRoot.getRenderKitId());
ResponseStateManager responseStateManager = renderKit.getResponseStateManager();
if (responseStateManager instanceof MyfacesResponseStateManager)
{
((MyfacesResponseStateManager)responseStateManager).writeStateAsUrlParams(facesContext,
serializedView);
}
else
{
log.error("ResponseStateManager of render kit " + uiViewRoot.getRenderKitId() + " is no MyfacesResponseStateManager and does not support saving state in url parameters.");
}
}
if (log.isTraceEnabled()) log.trace("Exiting writeStateAsUrlParams");
}
//helpers
protected RenderKitFactory getRenderKitFactory()
{
if (_renderKitFactory == null)
{
_renderKitFactory = (RenderKitFactory)FactoryFinder.getFactory(FactoryFinder.RENDER_KIT_FACTORY);
}
return _renderKitFactory;
}
protected void saveSerializedViewInServletSession(FacesContext context,
Object serializedView)
{
Map<String, Object> sessionMap = context.getExternalContext().getSessionMap();
SerializedViewCollection viewCollection = (SerializedViewCollection) sessionMap
.get(SERIALIZED_VIEW_SESSION_ATTR);
if (viewCollection == null)
{
viewCollection = new SerializedViewCollection();
sessionMap.put(SERIALIZED_VIEW_SESSION_ATTR, viewCollection);
}
viewCollection.add(context, serializeView(context, serializedView));
// replace the value to notify the container about the change
sessionMap.put(SERIALIZED_VIEW_SESSION_ATTR, viewCollection);
}
protected Object getSerializedViewFromServletSession(FacesContext context, String viewId, Integer sequence)
{
ExternalContext externalContext = context.getExternalContext();
Map<String, Object> requestMap = externalContext.getRequestMap();
Object serializedView = null;
if (requestMap.containsKey(RESTORED_SERIALIZED_VIEW_REQUEST_ATTR))
{
serializedView = requestMap.get(RESTORED_SERIALIZED_VIEW_REQUEST_ATTR);
}
else
{
SerializedViewCollection viewCollection = (SerializedViewCollection) externalContext
.getSessionMap().get(SERIALIZED_VIEW_SESSION_ATTR);
if (viewCollection != null)
{
/*
String sequenceStr = externalContext.getRequestParameterMap().get(
RendererUtils.SEQUENCE_PARAM);
Integer sequence = null;
if (sequenceStr == null)
{
// use latest sequence
Map map = externalContext.getSessionMap();
sequence = (Integer) map.get(RendererUtils.SEQUENCE_PARAM);
}
else
{
sequence = new Integer(sequenceStr);
}
*/
if (sequence != null)
{
Object state = viewCollection.get(sequence, viewId);
if (state != null)
{
serializedView = deserializeView(state);
}
}
}
requestMap.put(RESTORED_SERIALIZED_VIEW_REQUEST_ATTR, serializedView);
nextViewSequence(context);
}
return serializedView;
}
protected int getNextViewSequence(FacesContext context)
{
ExternalContext externalContext = context.getExternalContext();
if (!externalContext.getRequestMap().containsKey(RendererUtils.SEQUENCE_PARAM))
{
nextViewSequence(context);
}
Integer sequence = (Integer) externalContext.getRequestMap().get(RendererUtils.SEQUENCE_PARAM);
return sequence.intValue();
}
protected void nextViewSequence(FacesContext facescontext)
{
ExternalContext externalContext = facescontext.getExternalContext();
Object sessionObj = externalContext.getSession(true);
synchronized(sessionObj) // synchronized to increase sequence if multiple requests
// are handled at the same time for the session
{
Map<String, Object> map = externalContext.getSessionMap();
Integer sequence = (Integer) map.get(RendererUtils.SEQUENCE_PARAM);
if(sequence == null || sequence.intValue() == Integer.MAX_VALUE)
{
sequence = new Integer(1);
}
else
{
sequence = new Integer(sequence.intValue() + 1);
}
map.put(RendererUtils.SEQUENCE_PARAM, sequence);
externalContext.getRequestMap().put(RendererUtils.SEQUENCE_PARAM, sequence);
}
}
protected Object serializeView(FacesContext context, Object serializedView)
{
if (log.isTraceEnabled()) log.trace("Entering serializeView");
if(isSerializeStateInSession(context))
{
if (log.isTraceEnabled()) log.trace("Processing serializeView - serialize state in session");
ByteArrayOutputStream baos = new ByteArrayOutputStream(1024);
try
{
OutputStream os = baos;
if(isCompressStateInSession(context))
{
if (log.isTraceEnabled()) log.trace("Processing serializeView - serialize compressed");
os.write(COMPRESSED_FLAG);
os = new GZIPOutputStream(os, 1024);
}
else
{
if (log.isTraceEnabled()) log.trace("Processing serializeView - serialize uncompressed");
os.write(UNCOMPRESSED_FLAG);
}
Object[] stateArray = (Object[]) serializedView;
ObjectOutputStream out = new ObjectOutputStream(os);
out.writeObject(stateArray[0]);
out.writeObject(stateArray[1]);
out.close();
baos.close();
if (log.isTraceEnabled()) log.trace("Exiting serializeView - serialized. Bytes : "+baos.size());
return baos.toByteArray();
}
catch (IOException e)
{
log.error("Exiting serializeView - Could not serialize state: " + e.getMessage(), e);
return null;
}
}
if (log.isTraceEnabled())
log.trace("Exiting serializeView - do not serialize state in session.");
return serializedView;
}
/**
* Reads the value of the <code>org.apache.myfaces.SERIALIZE_STATE_IN_SESSION</code> context parameter.
* @see SERIALIZE_STATE_IN_SESSION_PARAM
* @param context <code>FacesContext</code> for the request we are processing.
* @return boolean true, if the server state should be serialized in the session
*/
protected boolean isSerializeStateInSession(FacesContext context)
{
String value = context.getExternalContext().getInitParameter(
SERIALIZE_STATE_IN_SESSION_PARAM);
boolean serialize = DEFAULT_SERIALIZE_STATE_IN_SESSION;
if (value != null)
{
serialize = Boolean.valueOf(value);
}
return serialize;
}
/**
* Reads the value of the <code>org.apache.myfaces.COMPRESS_STATE_IN_SESSION</code> context parameter.
* @see COMPRESS_SERVER_STATE_PARAM
* @param context <code>FacesContext</code> for the request we are processing.
* @return boolean true, if the server state steam should be compressed
*/
protected boolean isCompressStateInSession(FacesContext context)
{
String value = context.getExternalContext().getInitParameter(
COMPRESS_SERVER_STATE_PARAM);
boolean compress = DEFAULT_COMPRESS_SERVER_STATE_PARAM;
if (value != null)
{
compress = Boolean.valueOf(value);
}
return compress;
}
protected Object deserializeView(Object state)
{
if (log.isTraceEnabled()) log.trace("Entering deserializeView");
if(state instanceof byte[])
{
if (log.isTraceEnabled()) log.trace("Processing deserializeView - deserializing serialized state. Bytes : "+((byte[]) state).length);
try
{
ByteArrayInputStream bais = new ByteArrayInputStream((byte[]) state);
InputStream is = bais;
if(is.read() == COMPRESSED_FLAG)
{
is = new GZIPInputStream(is);
}
ObjectInputStream in = new MyFacesObjectInputStream(
is);
return new Object[] {in.readObject(), in.readObject()};
}
catch (IOException e)
{
log.error("Exiting deserializeView - Could not deserialize state: " + e.getMessage(), e);
return null;
}
catch (ClassNotFoundException e)
{
log.error("Exiting deserializeView - Could not deserialize state: " + e.getMessage(), e);
return null;
}
}
else if (state instanceof Object[])
{
if (log.isTraceEnabled()) log.trace("Exiting deserializeView - state not serialized.");
return state;
}
else if(state == null)
{
log.error("Exiting deserializeView - this method should not be called with a null-state.");
return null;
}
else
{
log.error("Exiting deserializeView - this method should not be called with a state of type : "+state.getClass());
return null;
}
}
private boolean isLegacyResponseStateManager(ResponseStateManager instance) {
Method[] methods = instance.getClass().getMethods();
for (Method m : methods)
{
if (m.getName().equals("getState") &&
Arrays.equals(m.getParameterTypes(),new Class[] {FacesContext.class, String.class}))
{
return false;
}
}
return true;
}
protected static class SerializedViewCollection implements Serializable
{
private static final long serialVersionUID = -3734849062185115847L;
private final List<Object> _keys = new ArrayList<Object>(DEFAULT_NUMBER_OF_VIEWS_IN_SESSION);
private final Map<Object, Object> _serializedViews = new HashMap<Object, Object>();
// old views will be hold as soft references which will be removed by
// the garbage collector if free memory is low
private transient Map<Object, Object> _oldSerializedViews = null;
public synchronized void add(FacesContext context, Object state)
{
Object key = new SerializedViewKey(context);
_serializedViews.put(key, state);
while (_keys.remove(key));
_keys.add(key);
int views = getNumberOfViewsInSession(context);
while (_keys.size() > views)
{
key = _keys.remove(0);
Object oldView = _serializedViews.remove(key);
if (oldView != null)
{
getOldSerializedViewsMap().put(key, oldView);
}
}
}
/**
* Reads the amount (default = 20) of views to be stored in session.
* @see NUMBER_OF_VIEWS_IN_SESSION_PARAM
* @param context FacesContext for the current request, we are processing
* @return Number vf views stored in the session
*/
protected int getNumberOfViewsInSession(FacesContext context)
{
String value = context.getExternalContext().getInitParameter(
NUMBER_OF_VIEWS_IN_SESSION_PARAM);
int views = DEFAULT_NUMBER_OF_VIEWS_IN_SESSION;
if (value != null)
{
try
{
views = Integer.parseInt(value);
if (views <= 0)
{
log.error("Configured value for " + NUMBER_OF_VIEWS_IN_SESSION_PARAM
+ " is not valid, must be an value > 0, using default value ("
+ DEFAULT_NUMBER_OF_VIEWS_IN_SESSION);
views = DEFAULT_NUMBER_OF_VIEWS_IN_SESSION;
}
}
catch (Throwable e)
{
log.error("Error determining the value for " + NUMBER_OF_VIEWS_IN_SESSION_PARAM
+ ", expected an integer value > 0, using default value ("
+ DEFAULT_NUMBER_OF_VIEWS_IN_SESSION + "): " + e.getMessage(), e);
}
}
return views;
}
/**
* @return old serialized views map
*/
protected Map<Object, Object> getOldSerializedViewsMap()
{
if (_oldSerializedViews == null)
{
_oldSerializedViews = new ReferenceMap(AbstractReferenceMap.WEAK, AbstractReferenceMap.WEAK, true);
}
return _oldSerializedViews;
}
public Object get(Integer sequence, String viewId)
{
Object key = new SerializedViewKey(viewId, sequence);
Object value = _serializedViews.get(key);
if (value == null)
{
value = getOldSerializedViewsMap().get(key);
}
return value;
}
}
protected static class SerializedViewKey implements Serializable
{
private static final long serialVersionUID = -1170697124386063642L;
private final String _viewId;
private final Integer _sequenceId;
public SerializedViewKey(String viewId, Integer sequence)
{
_sequenceId = sequence;
_viewId = viewId;
}
public SerializedViewKey(FacesContext context)
{
_sequenceId = RendererUtils.getViewSequence(context);
_viewId = context.getViewRoot().getViewId();
}
@Override
public int hashCode()
{
final int PRIME = 31;
int result = 1;
result = PRIME * result + ((_sequenceId == null) ? 0 : _sequenceId.hashCode());
result = PRIME * result + ((_viewId == null) ? 0 : _viewId.hashCode());
return result;
}
@Override
public boolean equals(Object obj)
{
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
final SerializedViewKey other = (SerializedViewKey) obj;
if (_sequenceId == null)
{
if (other._sequenceId != null)
return false;
}
else if (!_sequenceId.equals(other._sequenceId))
return false;
if (_viewId == null)
{
if (other._viewId != null)
return false;
}
else if (!_viewId.equals(other._viewId))
return false;
return true;
}
}
}