com.sun.faces.application.InjectionApplicationFactory Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of jakarta.faces Show documentation
EE4J Compatible Implementation for Jakarta Faces API
The newest version!
/*
 * Copyright (c) 1997, 2020 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 com.sun.faces.application;

import static com.sun.faces.util.Util.notNull;
import static java.text.MessageFormat.format;
import static java.util.logging.Level.FINE;
import static java.util.logging.Level.SEVERE;

import java.lang.reflect.Field;
import java.util.Map;
import java.util.logging.Logger;

import com.sun.faces.util.FacesLogger;

import jakarta.faces.application.Application;
import jakarta.faces.application.ApplicationFactory;
import jakarta.faces.context.FacesContext;

/**
 * This {@link jakarta.faces.application.ApplicationFactory} is responsible for injecting the default
 * {@link Application} instance into the top-level {@link Application} as configured by the runtime. Doing this allows
 * us to preserve backwards compatibility as the API evolves without having the API rely on implementation specific
 * details.
 */
public class InjectionApplicationFactory extends ApplicationFactory {

    private static final Logger LOGGER = FacesLogger.APPLICATION.getLogger();

    private Application defaultApplication;
    private Field defaultApplicationField;
    private volatile Application application;

    // ------------------------------------------------------------ Constructors

    public InjectionApplicationFactory(ApplicationFactory delegate) {
        super(delegate);
        notNull("applicationFactory", delegate);
    }

    // ----------------------------------------- Methods from ApplicationFactory

    @Override
    public Application getApplication() {

        if (application == null) {
            application = getWrapped().getApplication();

            if (application == null) {
                throw new IllegalStateException(
                        format("Delegate ApplicationContextFactory, {0}, returned null when calling getApplication().", getWrapped().getClass().getName()));
            }

            injectDefaultApplication();
        }

        return application;
    }

    @Override
    public synchronized void setApplication(Application application) {
        this.application = application;
        getWrapped().setApplication(application);
        injectDefaultApplication();
    }

    // --------------------------------------------------------- Private Methods

    private void injectDefaultApplication() {

        if (defaultApplication == null) {
            FacesContext ctx = FacesContext.getCurrentInstance();
            defaultApplication = InjectionApplicationFactory.removeApplicationInstance(ctx.getExternalContext().getApplicationMap());
        }

        if (defaultApplication != null) {
            try {
                if (defaultApplicationField == null) {
                    defaultApplicationField = Application.class.getDeclaredField("defaultApplication");
                    defaultApplicationField.setAccessible(true);
                }
                defaultApplicationField.set(application, defaultApplication);

            } catch (NoSuchFieldException nsfe) {
                if (LOGGER.isLoggable(FINE)) {
                    LOGGER.log(FINE, "Unable to find private field named 'defaultApplication' in jakarta.faces.application.Application.");
                }
            } catch (SecurityException | IllegalArgumentException | IllegalAccessException e) {
                if (LOGGER.isLoggable(SEVERE)) {
                    LOGGER.log(SEVERE, e.toString(), e);
                }
            }
        }
    }

    // ------------------------------------------------- Package private Methods

    static void setApplicationInstance(Application app) {
        FacesContext.getCurrentInstance().getExternalContext().getApplicationMap().put(InjectionApplicationFactory.class.getName(), app);
    }

    static Application removeApplicationInstance(Map appMap) {
        return (Application) appMap.remove(InjectionApplicationFactory.class.getName());
    }

}