FetchMap.java

/*
 * Copyright (C) 2011 eXo Platform SAS.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.gatein.portal.controller.resource.script;

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


/**
 * <p>
 * </p>
 * Extends an {@link HashMap} to add convenient method for safely adding a fetch mode to a map. The method
 * {@link #add(Object, FetchMode)} will add the mode only if the new mode implies the previous mode in the map.</p>
 *
 * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a>
 */
public class FetchMap<E> extends LinkedHashMap<E, FetchMode> {

    public FetchMap() {
    }

    public FetchMap(Map<? extends E, ? extends FetchMode> m) {
        super(m);
    }

    public boolean add(E element, FetchMode mode) throws NullPointerException {
        if (element == null) {
            throw new NullPointerException("No null element accepted");
        }

        //
        FetchMode prev = get(element);
        if (prev == null) {
            put(element, mode);
            return true;
        } else if (mode != null && mode.compareTo(prev) >= 0) {
            put(element, mode);
            return true;
        } else {
            return false;
        }
    }

    public boolean add(E element) throws NullPointerException {
        return add(element, null);
    }

    public void addAll(Map<E, FetchMode> m) {
        for (E elem : m.keySet()) {
            add(elem, m.get(elem));
        }
    }
}