Glassfish example source code file (EventTypes.java)

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Java - Glassfish tags/keywords

class, class, eventtypes, eventtypes, hashmap, map, override, server_shutdown, server_startup, server_startup_name, string, string, t, t, util

The Glassfish EventTypes.java source code

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
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 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package org.glassfish.api.event;

import java.util.HashMap;
import java.util.Map;

/**
 * Extensible list of event types.
 * EventTypes are created through the create method and not directly.
 * 
 * Events can be compared using == or equals although == is recommended.
 * 
 * @author dochez
 */
public final class EventTypes<T> {
    
    private final static Map<String, EventTypes> EVENTS=new HashMap();

    
    // stock events.
    public static final String SERVER_STARTUP_NAME = "server_startup";
    public static final String SERVER_READY_NAME = "server_ready";
    public static final String PREPARE_SHUTDOWN_NAME = "prepare_shutdown";
    public static final String SERVER_SHUTDOWN_NAME = "server_shutdown";

    public static final EventTypes SERVER_STARTUP = create(SERVER_STARTUP_NAME);
    public static final EventTypes SERVER_READY = create(SERVER_READY_NAME);
    public static final EventTypes SERVER_SHUTDOWN = create(SERVER_SHUTDOWN_NAME);
    public static final EventTypes PREPARE_SHUTDOWN = create(PREPARE_SHUTDOWN_NAME);

    public static EventTypes create(String name) {
        return create(name, null);
    }

    public static <T> EventTypes create(String name, Class hookType) {
        synchronized(EVENTS) {
            if (!EVENTS.containsKey(name)) {
                EVENTS.put(name, new EventTypes(name, hookType));
            }
        }
        return EVENTS.get(name);
    }    
    
    private final String name;
    private final Class<T> hookType;

    private EventTypes(String name, Class<T> hookType) {
        this.name = name;
        this.hookType = hookType;
    }
    
    public String type() {
        return name;
    }

    public Class<T> getHookType() {
        return hookType;
    }


    public T getHook(EventListener.Event<T> e) {
        if (e.is(this)) {
            return e.hook();
        }
        return null;
    }
    
    /**
     * {@inheritDoc}
     * <p/>
     * Considers only {@link #name} for equality.
     */
    @Override
    public boolean equals(final Object o) {
        if (this == o) return true;
        if (null == o) return false;
        if (getClass() != o.getClass()) return false;

        return name.equals(((EventTypes) o).name);
    }

    /**
     * {@inheritDoc}
     * <p/>
     * Returns {@link #name} as the hash code.
     */
    @Override
    public int hashCode() {
        return name.hashCode();
    }      
    
}