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 }