javax.faces.context.FlashFactory Maven / Gradle / Ivy
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/*
* Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package javax.faces.context;
import javax.faces.FacesWrapper;
/**
* FlashFactory is a
* factory object that creates (if needed) and returns {@link Flash}
* instances. Implementations of JavaServer Faces must provide at
* least a default implementation of {@link Flash}.
*
*
* There must be one {@link FlashFactory} instance per web
* application that is utilizing JavaServer Faces. This instance can
* be acquired, in a portable manner, by calling:
*
* FlashFactory factory = (FlashFactory)
* FactoryFinder.getFactory(FactoryFinder.FLASH_FACTORY);
*
* The common way to access the flash instance from Java code is
* still via {@link ExternalContext#getFlash}. The common way to access
* the flash from Faces views is the implicit EL object "flash". The
* runtime must ensure that the FlashFactory is used to
* instantiate the flash.
*
*
* Usage: extend this class and push the implementation being wrapped to the
* constructor and use {@link #getWrapped} to access the instance being wrapped.
*
* @since 2.2
*/
public abstract class FlashFactory implements FacesWrapper {
private FlashFactory wrapped;
/**
* @deprecated Use the other constructor taking the implementation being wrapped.
*/
@Deprecated
public FlashFactory() {
}
/**
* If this factory has been decorated,
* the implementation doing the decorating should push the implementation being wrapped to this constructor.
* The {@link #getWrapped()} will then return the implementation being wrapped.
*
* @param wrapped The implementation being wrapped.
*/
public FlashFactory(FlashFactory wrapped) {
this.wrapped = wrapped;
}
/**
* If this factory has been decorated, the
* implementation doing the decorating may override this method to provide
* access to the implementation being wrapped.
*/
@Override
public FlashFactory getWrapped() {
return wrapped;
}
/**
* Create (if needed) and return a
* {@link Flash} instance for this web application.
*
* @param create true to create a new instance for this request if
* necessary; false to return null if there's no
* instance in the current session.
*
* @return the instance of Flash.
*
* @since 2.2
*/
public abstract Flash getFlash(boolean create);
}