001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.camel.processor.resequencer;
018    
019    import java.util.Comparator;
020    
021    /**
022     * A strategy for comparing elements of a sequence.
023     * 
024     * @author Martin Krasser
025     * 
026     * @version $Revision: 747062 $
027     */
028    public interface SequenceElementComparator<E> extends Comparator<E> {
029    
030        /**
031         * Returns <code>true</code> if <code>o1</code> is an immediate predecessor
032         * of <code>o2</code>.
033         * 
034         * @param o1 a sequence element.
035         * @param o2 a sequence element.
036         * @return true if its an immediate predecessor
037         */
038        boolean predecessor(E o1, E o2);
039        
040        /**
041         * Returns <code>true</code> if <code>o1</code> is an immediate successor
042         * of <code>o2</code>.
043         * 
044         * @param o1 a sequence element.
045         * @param o2 a sequence element.
046         * @return true if its an immediate sucessor
047         */
048        boolean successor(E o1, E o2);
049        
050    }