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/*
* Copyright (c) 1997, 2021 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 jakarta.faces.view.facelets;
import java.io.IOException;
import java.net.URL;
/**
*
* This API defines the facility by which the Facelets
* {@link jakarta.faces.view.ViewDeclarationLanguage} creates and caches instances of Facelets.
*
*
*
* The cache handles two different kinds of Facelets: View Facelets and View Metadata Facelets. The former is the usual
* Facelet that provides for the construction of a UIComponent tree. This kind of Facelet is accessed via
* the {@link #getFacelet} and {@link #isFaceletCached} methods. The latter is a special kind of Facelet that
* corresponds to {@link jakarta.faces.view.ViewDeclarationLanguage#getViewMetadata}. This kind of Facelet is accessed
* via the {@link #getViewMetadataFacelet} and {@link #isViewMetadataFaceletCached} methods.
*
*
* @since 2.1
*/
public abstract class FaceletCache {
private MemberFactory memberFactory;
private MemberFactory viewMetadataMemberFactory;
/**
*
* Factory interface for creating Facelet or View Metadata Facelet instances.
*
*/
public interface MemberFactory {
/**
*
* Create a Facelet or View Metadata Facelet (depending on the type of factory this is) for the argument URL.
*
*
* @param key the URL that will be used as the key for the instance being created.
*
* @throws NullPointerException if argument key is null.
*
* @throws IOException if unable to load a file necessary to respond to service this method.
*
* @return the newly created {@code Facelet} or View Metadata {@code Facelet}
*/
V newInstance(final URL key) throws IOException;
}
/**
*
* Returns a cached Facelet instance. If no instance is available, it will be created using the Facelet
* {@link MemberFactory} and stored in the cache.
*
*
* @param url URL for the Facelet being retrieved
*
* @throws NullPointerException if argument url is null.
*
* @throws IOException if unable to load a file necessary to respond to service this method.
*
* @return a cached or new {@code Facelet}
*
*/
public abstract V getFacelet(URL url) throws IOException;
/**
*
*
* Determines whether a cached Facelet instance exists for this URL. Returns true if a cached instance exists, false
* otherwise
*
*
* @param url URL for the Facelet
*
* @throws NullPointerException if argument url is null.
*
* @return true if a cached instance exists, false otherwise
*
*/
public abstract boolean isFaceletCached(URL url);
/**
*
* Returns a cached View Metadata Facelet instance. If no instance is available, it will be created using the View
* Metadata Facelet {@link MemberFactory} and stored in the cache.
*
*
* @param url URL for the View Metadata Facelet being retrieved
*
* @throws NullPointerException if argument url is null.
*
* @throws IOException if unable to load a file necessary to respond to service this method.
*
* @return a cached or new View Metadata {@code Facelet} instance
*
*/
public abstract V getViewMetadataFacelet(URL url) throws IOException;
/**
*
* Determines whether a cached View Metadata Facelet instance exists for this URL. Returns true if a cached instance
* exists, false otherwise
*
*
* @param url URL for the View Metadata Facelet
*
* @throws NullPointerException if argument url is null.
*
* @return true if a cached instance exists, false otherwise
*/
public abstract boolean isViewMetadataFaceletCached(URL url);
/**
*
*
* This must be called by the runtime at startup time, before any requests are serviced, and allows for the
* FaceletCache implementation to provide the {@link MemberFactory} instances that will be used to create
* instances of Facelets and View Metadata Facelets.
*
*
* @param faceletFactory the {@link MemberFactory} instance that will be used to create instances of Facelets.
*
* @param viewMetadataFaceletFactory the {@link MemberFactory} instance that will be used to create instances of
* metadata Facelets.
*
* @throws NullPointerException if either argument is null
*
* @since 2.3
*/
public void setCacheFactories(MemberFactory faceletFactory, MemberFactory viewMetadataFaceletFactory) {
if (null == faceletFactory || null == viewMetadataFaceletFactory) {
throw new NullPointerException("Neither faceletFactory no viewMetadataFaceletFactory may be null.");
}
this.memberFactory = faceletFactory;
this.viewMetadataMemberFactory = viewMetadataFaceletFactory;
}
/**
*
* Returns the {@link MemberFactory} passed to {@link #setCacheFactories} for the purpose of creating Facelet instance.
*
*
* @return the {@link MemberFactory} passed to {@link #setCacheFactories} for the purpose of creating Facelet instance.
*/
protected MemberFactory getMemberFactory() {
return memberFactory;
}
/**
*
* Returns the {@link MemberFactory} passed to {@link #setCacheFactories} for the purpose of creating View Metadata
* Facelet instance.
*
*
* @return the {@link MemberFactory} passed to {@link #setCacheFactories} for the purpose of creating View Metadata
* Facelet instance.
*/
protected MemberFactory getMetadataMemberFactory() {
return viewMetadataMemberFactory;
}
}