GenericComparator.java

/**
 * Copyright 1999-2009 The Pegadi Team
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.pegadi.articlelist;

// pegadi-imports

import java.util.Comparator;

/**
 * A generic three-layer @link{Comparator} for comparing/sorting
 * articles by various parameters (ArticleType, Publication,
 * Journalist, Characters, etc...)
 *
 * @author <a href="mailto:jb@underdusken.no">Jørgen Binningsbø</a>
 * @version $Id$
 * @see Comparator
 */
public class GenericComparator implements Comparator {

    Comparator comparator1;
    Comparator comparator2;
    Comparator comparator3;

    public GenericComparator(Comparator comparator1, Comparator
            comparator2, Comparator comparator3) {
        initialize(comparator1, comparator2, comparator3);
    }

    public GenericComparator(Comparator comparator1, Comparator
            comparator2) {
        initialize(comparator1, comparator2, null);
    }

    public GenericComparator(Comparator comparator1) {
        initialize(comparator1, null, null);
    }

    protected void initialize(Comparator comparator1, Comparator
            comparator2, Comparator comparator3) {
        this.comparator1 = comparator1;
        this.comparator2 = comparator2;
        this.comparator3 = comparator3;

    }

    public int compare(Object o1, Object o2) {
        int lastCmp = comparator1.compare(o1, o2);
        if (lastCmp == 0 & comparator2 != null) {
            lastCmp = comparator2.compare(o1, o2);
            if (lastCmp == 0 & comparator3 != null) {
                lastCmp = comparator3.compare(o1, o2);
            }
        }
        return lastCmp;
    }
}