001 /** 002 * 003 * Licensed to the Apache Software Foundation (ASF) under one or more 004 * contributor license agreements. See the NOTICE file distributed with 005 * this work for additional information regarding copyright ownership. 006 * The ASF licenses this file to You under the Apache License, Version 2.0 007 * (the "License"); you may not use this file except in compliance with 008 * the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018 package org.apache.camel.util; 019 020 import org.apache.camel.Exchange; 021 import org.apache.camel.Expression; 022 023 import java.util.Comparator; 024 import java.util.List; 025 026 /** 027 * An implementation of {@link java.util.Comparator} which takes a list of 028 * {@link org.apache.camel.Expression} objects which is evaluated 029 * on each exchange to compare them 030 * 031 * @version $Revision: 1.1 $ 032 */ 033 public class ExpressionListComparator<E extends Exchange> implements Comparator<E> { 034 private final List<Expression<E>> expressions; 035 036 public ExpressionListComparator(List<Expression<E>> expressions) { 037 this.expressions = expressions; 038 } 039 040 public int compare(E e1, E e2) { 041 for (Expression<E> expression : expressions) { 042 Object o1 = expression.evaluate(e1); 043 Object o2 = expression.evaluate(e2); 044 int answer = ObjectHelper.compare(o1, o2); 045 if (answer != 0) { 046 return answer; 047 } 048 } 049 return 0; 050 } 051 }