com.sun.faces.application.applicationimpl.events.EventInfo Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of jakarta.faces-api Show documentation

Jakarta Faces defines an MVC framework for building user interfaces for web applications, including UI components, state management, event handing, input validation, page navigation, and support for internationalization and accessibility.

There is a newer version: 4.1.2

Show 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.applicationimpl.events;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.logging.Level;
import java.util.logging.Logger;

import com.sun.faces.util.FacesLogger;

import jakarta.faces.FacesException;
import jakarta.faces.event.SystemEvent;
import jakarta.faces.event.SystemEventListener;

/**
 * Represent a logical association between a SystemEvent and a Source. This call will contain the Listeners specific to
 * this association as well as provide a method to construct new SystemEvents as required.
 */
public class EventInfo {

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

    private final Class systemEvent;
    private final Class sourceClass;
    private final Set listeners;
    private Constructor eventConstructor;
    private final Map, Constructor> constructorMap;

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

    public EventInfo(Class systemEvent, Class sourceClass) {

        this.systemEvent = systemEvent;
        this.sourceClass = sourceClass;
        listeners = new CopyOnWriteArraySet<>();
        constructorMap = new HashMap<>();
        if (!sourceClass.equals(Void.class)) {
            eventConstructor = getEventConstructor(sourceClass);
        }

    }

    // ------------------------------------------------------ Public Methods

    public Set getListeners() {

        return listeners;

    }

    public SystemEvent createSystemEvent(Object source) {

        Constructor toInvoke = getCachedConstructor(source.getClass());
        if (toInvoke != null) {
            try {
                return (SystemEvent) toInvoke.newInstance(source);
            } catch (InstantiationException | IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
                throw new FacesException(e);
            }
        }
        return null;

    }

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

    private Constructor getCachedConstructor(Class source) {

        if (eventConstructor != null) {
            return eventConstructor;
        } else {
            Constructor c = constructorMap.get(source);
            if (c == null) {
                c = getEventConstructor(source);
                if (c != null) {
                    constructorMap.put(source, c);
                }
            }
            return c;
        }

    }

    private Constructor getEventConstructor(Class source) {

        Constructor ctor = null;
        try {
            return systemEvent.getDeclaredConstructor(source);
        } catch (NoSuchMethodException ignored) {
            Constructor[] ctors = systemEvent.getConstructors();
            if (ctors != null) {
                for (Constructor c : ctors) {
                    Class[] params = c.getParameterTypes();
                    if (params.length != 1) {
                        continue;
                    }
                    if (params[0].isAssignableFrom(source)) {
                        return c;
                    }
                }
            }
            if (eventConstructor == null && LOGGER.isLoggable(Level.FINE)) {
                LOGGER.log(Level.FINE, "Unable to find Constructor within {0} that accepts {1} instances.",
                        new Object[] { systemEvent.getName(), sourceClass.getName() });
            }
        }
        return ctor;

    }

}