/*
* 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.application.jsp;
import org.apache.commons.collections.map.ReferenceMap;
import org.apache.commons.collections.map.AbstractReferenceMap;
import org.apache.commons.lang.builder.EqualsBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;
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.ViewSequenceUtils;
import org.apache.myfaces.shared_impl.util.MyFacesObjectInputStream;
import javax.faces.FactoryFinder;
import javax.faces.application.StateManager;
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.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: lu4242 $)
* @author Manfred Geiler
* @version $Revision: 694453 $ $Date: 2008-09-11 15:12:45 -0500 (Thu, 11 Sep 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.
*/
/**
* 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.
*/
/**
* 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;
/**
* Define the way of handle old view references(views removed from session), making possible to
* store it in a cache, so the state manager first try to get the view from the session. If is it
* not found and soft or weak ReferenceMap is used, it try to get from it.
* <p>
* Only applicable if state saving method is "server" (= default).
* </p>
* <p>
* The gc is responsible for remove the views, according to the rules used for soft, weak or phantom
* references. If a key in soft and weak mode is garbage collected, its values are purged.
* </p>
* <p>
* By default no cache is used, so views removed from session became phantom references.
* </p>
* <ul>
* <li> off, no: default, no cache is used</li>
* <li> hard-soft: use an ReferenceMap(AbstractReferenceMap.HARD, AbstractReferenceMap.SOFT)</li>
* <li> soft: use an ReferenceMap(AbstractReferenceMap.SOFT, AbstractReferenceMap.SOFT, true) </li>
* <li> soft-weak: use an ReferenceMap(AbstractReferenceMap.SOFT, AbstractReferenceMap.WEAK, true) </li>
* <li> weak: use an ReferenceMap(AbstractReferenceMap.WEAK, AbstractReferenceMap.WEAK, true) </li>
* </ul>
*
*/
private static final String CACHE_OLD_VIEWS_IN_SESSION_MODE = "org.apache.myfaces.CACHE_OLD_VIEWS_IN_SESSION_MODE";
/**
* This option uses an hard-soft ReferenceMap, but it could cause a
* memory leak, because the keys are not removed by any method
* (MYFACES-1660). So use with caution.
*/
private static final String CACHE_OLD_VIEWS_IN_SESSION_MODE_HARD_SOFT = "hard-soft";
private static final String CACHE_OLD_VIEWS_IN_SESSION_MODE_SOFT = "soft";
private static final String CACHE_OLD_VIEWS_IN_SESSION_MODE_SOFT_WEAK = "soft-weak";
private static final String CACHE_OLD_VIEWS_IN_SESSION_MODE_WEAK = "weak";
private static final String CACHE_OLD_VIEWS_IN_SESSION_MODE_OFF = "off";
private static final int UNCOMPRESSED_FLAG = 0;
private static final int COMPRESSED_FLAG = 1;
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
//===========================================
Object serializedComponentStates;
if (isSavingStateInClient(facesContext)) {
RenderKit renderKit = getRenderKitFactory().getRenderKit(facesContext, renderKitId);
ResponseStateManager responseStateManager = renderKit.getResponseStateManager();
serializedComponentStates = responseStateManager.getComponentStateToRestore(facesContext);
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 {
String viewId = uiViewRoot.getViewId();
String sequenceStr = getSequenceString(facesContext, renderKitId, viewId);
SerializedView serializedView = getSerializedViewFromServletSession(facesContext,
viewId,
sequenceStr);
if (serializedView == null) {
log.error("No serialized view found in server session!");
// mark UIViewRoot invalid by resetting view id
uiViewRoot.setViewId(null);
return;
}
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");
}
/**
* See getTreeStructureToSave.
*/
protected UIViewRoot restoreTreeStructure(FacesContext facesContext,
String viewId,
String renderKitId) {
if (log.isTraceEnabled()) log.trace("Entering restoreTreeStructure");
UIViewRoot uiViewRoot;
if (isSavingStateInClient(facesContext)) {
//reconstruct tree structure from request
RenderKit rk = getRenderKitFactory().getRenderKit(facesContext, renderKitId);
ResponseStateManager responseStateManager = rk.getResponseStateManager();
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((TreeStructureManager.TreeStructComponent) treeStructure);
if (log.isTraceEnabled()) log.trace("Tree structure restored from client request");
}
else {
String sequenceStr = getSequenceString(facesContext, renderKitId, viewId);
//reconstruct tree structure from ServletSession
SerializedView serializedView = getSerializedViewFromServletSession(facesContext,
viewId,
sequenceStr);
if (serializedView == null) {
if (log.isDebugEnabled())
log.debug("Exiting restoreTreeStructure - No serialized view found in server session!");
return null;
}
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((TreeStructureManager.TreeStructComponent) serializedView.getStructure());
if (log.isTraceEnabled()) log.trace("Tree structure restored from server session");
}
if (log.isTraceEnabled()) log.trace("Exiting restoreTreeStructure");
return uiViewRoot;
}
private String getSequenceString(FacesContext facesContext, String renderKitId, String viewId) {
RenderKit rk = getRenderKitFactory().getRenderKit(facesContext, renderKitId);
if(rk==null) //first access of the renderkit in a typical application - at this point, renderkit needs to be available. if it isn't we'll throw an exception
throw new NullPointerException("RenderKit for renderKitId : "+renderKitId + " on viewId : " + viewId + " could not be retrieved. Please specify a valid renderkit-id.");
ResponseStateManager responseStateManager = rk.getResponseStateManager();
String sequenceStr = (String) responseStateManager.getTreeStructureToRestore(facesContext, viewId);
return sequenceStr;
}
public UIViewRoot restoreView(FacesContext facescontext, String viewId, String renderKitId) {
if (log.isTraceEnabled()) log.trace("Entering restoreView");
UIViewRoot uiViewRoot = restoreTreeStructure(facescontext, viewId, renderKitId);
if (uiViewRoot != null) {
uiViewRoot.setViewId(viewId);
restoreComponentState(facescontext, uiViewRoot, renderKitId);
String restoredViewId = uiViewRoot.getViewId();
if (restoredViewId == null || !(restoredViewId.equals(viewId))) {
if (log.isTraceEnabled()) log.trace("Exiting restoreView - restored view is null.");
return null;
}
}
if (log.isTraceEnabled()) log.trace("Exiting restoreView");
return uiViewRoot;
}
public SerializedView saveSerializedView(FacesContext facesContext) throws IllegalStateException {
if (log.isTraceEnabled()) log.trace("Entering saveSerializedView");
checkForDuplicateIds(facesContext, facesContext.getViewRoot(), new HashSet());
if (log.isTraceEnabled()) log.trace("Processing saveSerializedView - Checked for duplicate Ids");
ExternalContext externalContext = facesContext.getExternalContext();
// SerializedView already created before within this request?
SerializedView serializedView = (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 StateManager.SerializedView(treeStruct, compStates);
externalContext.getRequestMap().put(SERIALIZED_VIEW_REQUEST_ATTR,
serializedView);
if (log.isTraceEnabled()) log.trace("Processing saveSerializedView - new serialized view created");
}
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");
Integer sequence = ViewSequenceUtils.getViewSequence(facesContext);
return new SerializedView(sequence.toString(), null);
}
if (log.isTraceEnabled()) log.trace("Exiting saveSerializedView - client-side state saving");
return serializedView;
}
private static void checkForDuplicateIds(FacesContext context,
UIComponent component,
Set 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();
}
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");
if (log.isTraceEnabled())
log.trace("Processing writeState - either client-side (full state) or server-side (partial information; e.g. sequence)");
if (serializedView != null) {
UIViewRoot uiViewRoot = facesContext.getViewRoot();
//save state in response (client-side: full state; server-side: sequence)
RenderKit renderKit = getRenderKitFactory().getRenderKit(facesContext, uiViewRoot.getRenderKitId());
renderKit.getResponseStateManager().writeState(facesContext, serializedView);
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,
SerializedView serializedView) {
Map 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 SerializedView getSerializedViewFromServletSession(FacesContext context, String viewId, String sequenceStr) {
ExternalContext externalContext = context.getExternalContext();
Map requestMap = externalContext.getRequestMap();
SerializedView serializedView = null;
if (requestMap.containsKey(RESTORED_SERIALIZED_VIEW_REQUEST_ATTR)) {
serializedView = (SerializedView) requestMap.get(RESTORED_SERIALIZED_VIEW_REQUEST_ATTR);
}
else {
SerializedViewCollection viewCollection = (SerializedViewCollection) externalContext
.getSessionMap().get(SERIALIZED_VIEW_SESSION_ATTR);
if (viewCollection != null) {
Integer sequence = null;
if (sequenceStr == null) {
// use latest sequence
sequence = ViewSequenceUtils.getCurrentSequence(context);
}
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);
ViewSequenceUtils.nextViewSequence(context);
}
return serializedView;
}
protected Object serializeView(FacesContext context, SerializedView 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);
}
ObjectOutputStream out = new ObjectOutputStream(os);
out.writeObject(serializedView.getStructure());
out.writeObject(serializedView.getState());
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;
}
}
else {
if (log.isTraceEnabled()) log.trace("Exiting serializeView - do not serialize state in session.");
return new Object[]{serializedView.getStructure(), serializedView.getState()};
}
}
/**
* Reads the value of the <code>org.apache.myfaces.SERIALIZE_STATE_IN_SESSION</code> context parameter.
*
* @param context <code>FacesContext</code> for the request we are processing.
* @return boolean true, if the server state should be serialized in the session
* @see SERIALIZE_STATE_IN_SESSION_PARAM
*/
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 = new Boolean(value).booleanValue();
}
return serialize;
}
/**
* Reads the value of the <code>org.apache.myfaces.COMPRESS_STATE_IN_SESSION</code> context parameter.
*
* @param context <code>FacesContext</code> for the request we are processing.
* @return boolean true, if the server state steam should be compressed
* @see COMPRESS_SERVER_STATE_PARAM
*/
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 = new Boolean(value).booleanValue();
}
return compress;
}
protected SerializedView 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 SerializedView(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.");
Object[] value = (Object[]) state;
return new SerializedView(value[0], value[1]);
}
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;
}
}
protected static class SerializedViewCollection implements Serializable {
private static final long serialVersionUID = -3734849062185115847L;
private final List _keys = new ArrayList(DEFAULT_NUMBER_OF_VIEWS_IN_SESSION);
private final Map _serializedViews = new HashMap();
// old views will be hold as soft references which will be removed by
// the garbage collector if free memory is low
private transient Map _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 &&
!CACHE_OLD_VIEWS_IN_SESSION_MODE_OFF.equals(getCacheOldViewsInSessionMode(context)))
{
getOldSerializedViewsMap().put(key, oldView);
}
}
}
/**
* Reads the amount (default = 20) of views to be stored in session.
*
* @param context FacesContext for the current request, we are processing
* @return Number vf views stored in the session
* @see NUMBER_OF_VIEWS_IN_SESSION_PARAM
*/
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 getOldSerializedViewsMap() {
FacesContext context = FacesContext.getCurrentInstance();
if (_oldSerializedViews == null && context != null)
{
String cacheMode = getCacheOldViewsInSessionMode(context);
if (CACHE_OLD_VIEWS_IN_SESSION_MODE_WEAK.equals(cacheMode))
{
_oldSerializedViews = new ReferenceMap(AbstractReferenceMap.WEAK, AbstractReferenceMap.WEAK, true);
}
else if (CACHE_OLD_VIEWS_IN_SESSION_MODE_SOFT_WEAK.equals(cacheMode))
{
_oldSerializedViews = new ReferenceMap(AbstractReferenceMap.SOFT, AbstractReferenceMap.WEAK, true);
}
else if (CACHE_OLD_VIEWS_IN_SESSION_MODE_SOFT.equals(cacheMode))
{
_oldSerializedViews = new ReferenceMap(AbstractReferenceMap.SOFT, AbstractReferenceMap.SOFT, true);
}
else if (CACHE_OLD_VIEWS_IN_SESSION_MODE_HARD_SOFT.equals(cacheMode))
{
_oldSerializedViews = new ReferenceMap(AbstractReferenceMap.HARD, AbstractReferenceMap.SOFT);
}
}
return _oldSerializedViews;
}
/**
* Reads the value of the <code>org.apache.myfaces.CACHE_OLD_VIEWS_IN_SESSION_MODE</code> context parameter.
*
* @since 1.1.7
* @param context
* @return constant indicating caching mode
* @see CACHE_OLD_VIEWS_IN_SESSION_MODE
*/
protected String getCacheOldViewsInSessionMode(FacesContext context) {
String value = context.getExternalContext().getInitParameter(
CACHE_OLD_VIEWS_IN_SESSION_MODE);
if (value == null)
{
return CACHE_OLD_VIEWS_IN_SESSION_MODE_OFF;
}
else if (value.equalsIgnoreCase(CACHE_OLD_VIEWS_IN_SESSION_MODE_SOFT))
{
return CACHE_OLD_VIEWS_IN_SESSION_MODE_SOFT;
}
else if (value.equalsIgnoreCase(CACHE_OLD_VIEWS_IN_SESSION_MODE_SOFT_WEAK))
{
return CACHE_OLD_VIEWS_IN_SESSION_MODE_SOFT_WEAK;
}
else if (value.equalsIgnoreCase(CACHE_OLD_VIEWS_IN_SESSION_MODE_WEAK))
{
return CACHE_OLD_VIEWS_IN_SESSION_MODE_WEAK;
}
else if (value.equalsIgnoreCase(CACHE_OLD_VIEWS_IN_SESSION_MODE_HARD_SOFT))
{
return CACHE_OLD_VIEWS_IN_SESSION_MODE_HARD_SOFT;
}
else
{
return CACHE_OLD_VIEWS_IN_SESSION_MODE_OFF;
}
}
public Object get(Integer sequence, String viewId) {
Object key = new SerializedViewKey(viewId, sequence);
Object value = _serializedViews.get(key);
if (value == null)
{
Map oldSerializedViewMap = getOldSerializedViewsMap();
if (oldSerializedViewMap != null)
{
value = oldSerializedViewMap.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 = ViewSequenceUtils.getViewSequence(context);
_viewId = context.getViewRoot().getViewId();
}
public boolean equals(Object obj) {
if (obj == null) {
return false;
}
if (obj == this) {
return true;
}
if (obj instanceof SerializedViewKey) {
SerializedViewKey other = (SerializedViewKey) obj;
return new EqualsBuilder().append(other._viewId, _viewId).append(other._sequenceId,
_sequenceId).isEquals();
}
return false;
}
public int hashCode() {
return new HashCodeBuilder().append(_viewId).append(_sequenceId).toHashCode();
}
}
}