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 */ 017package org.apache.camel.processor.resequencer; 018 019import java.util.Comparator; 020 021/** 022 * A strategy for comparing elements of a sequence. 023 * 024 * @version 025 */ 026public interface SequenceElementComparator<E> extends Comparator<E> { 027 028 /** 029 * Returns <code>true</code> if <code>o1</code> is an immediate predecessor 030 * of <code>o2</code>. 031 * 032 * @param o1 a sequence element. 033 * @param o2 a sequence element. 034 * @return true if its an immediate predecessor 035 */ 036 boolean predecessor(E o1, E o2); 037 038 /** 039 * Returns <code>true</code> if <code>o1</code> is an immediate successor 040 * of <code>o2</code>. 041 * 042 * @param o1 a sequence element. 043 * @param o2 a sequence element. 044 * @return true if its an immediate successor 045 */ 046 boolean successor(E o1, E o2); 047 048 /** 049 * Returns <tt>true</tt> if the <code>o1</code> can be used in this comparator. 050 * 051 * @param o1 a sequence element 052 * @return true if its usable for this comparator 053 */ 054 boolean isValid(E o1); 055 056}