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Central module for Tapestry, containing interfaces to the Java
Servlet API and all core services and components.
// Copyright 2007, 2008, 2010 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.tapestry5.internal.services;
import static org.apache.tapestry5.ioc.internal.util.CollectionFactory.newConcurrentMap;
import java.util.Map;
import org.apache.tapestry5.ioc.ObjectLocator;
import org.apache.tapestry5.services.ApplicationStateContribution;
import org.apache.tapestry5.services.ApplicationStateCreator;
import org.apache.tapestry5.services.ApplicationStateManager;
import org.apache.tapestry5.services.ApplicationStatePersistenceStrategy;
import org.apache.tapestry5.services.ApplicationStatePersistenceStrategySource;
public class ApplicationStateManagerImpl implements ApplicationStateManager
{
static final String DEFAULT_STRATEGY = "session";
static class ApplicationStateAdapter
{
private final Class ssoClass;
private final ApplicationStatePersistenceStrategy strategy;
private final ApplicationStateCreator creator;
ApplicationStateAdapter(Class ssoClass, ApplicationStatePersistenceStrategy strategy,
ApplicationStateCreator creator)
{
this.ssoClass = ssoClass;
this.strategy = strategy;
this.creator = creator;
}
T getOrCreate()
{
return strategy.get(ssoClass, creator);
}
void set(T sso)
{
strategy.set(ssoClass, sso);
}
boolean exists()
{
return strategy.exists(ssoClass);
}
}
/**
* The map will be extended periodically as new ASOs, not in the configuration, are encountered.
* Thut is is thread
* safe.
*/
private final Map classToAdapter = newConcurrentMap();
private final ApplicationStatePersistenceStrategySource source;
private final ObjectLocator locator;
@SuppressWarnings("unchecked")
public ApplicationStateManagerImpl(Map configuration,
ApplicationStatePersistenceStrategySource source, ObjectLocator locator)
{
this.source = source;
this.locator = locator;
for (Class asoClass : configuration.keySet())
{
ApplicationStateContribution contribution = configuration.get(asoClass);
ApplicationStateAdapter adapter = newAdapter(asoClass, contribution.getStrategy(),
contribution.getCreator());
classToAdapter.put(asoClass, adapter);
}
}
@SuppressWarnings("unchecked")
private ApplicationStateAdapter newAdapter(final Class ssoClass, String strategyName,
ApplicationStateCreator creator)
{
if (creator == null)
{
creator = new ApplicationStateCreator()
{
public T create()
{
return locator.autobuild("Instantiating instance of SSO class "
+ ssoClass.getName(), ssoClass);
}
};
}
ApplicationStatePersistenceStrategy strategy = source.get(strategyName);
return new ApplicationStateAdapter(ssoClass, strategy, creator);
}
@SuppressWarnings("unchecked")
private ApplicationStateAdapter getAdapter(Class ssoClass)
{
ApplicationStateAdapter result = classToAdapter.get(ssoClass);
// Not found is completely OK, we'll define it on the fly.
if (result == null)
{
result = newAdapter(ssoClass, DEFAULT_STRATEGY, null);
classToAdapter.put(ssoClass, result);
}
return result;
}
public T get(Class ssoClass)
{
return getAdapter(ssoClass).getOrCreate();
}
public T getIfExists(Class ssoClass)
{
ApplicationStateAdapter adapter = getAdapter(ssoClass);
return adapter.exists() ? adapter.getOrCreate() : null;
}
public void set(Class ssoClass, T sso)
{
getAdapter(ssoClass).set(sso);
}
public boolean exists(Class ssoClass)
{
return getAdapter(ssoClass).exists();
}
}