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.util;
018
019 import java.util.Comparator;
020 import java.util.List;
021
022 import org.apache.camel.Exchange;
023 import org.apache.camel.Expression;
024
025 /**
026 * An implementation of {@link java.util.Comparator} which takes a list of
027 * {@link org.apache.camel.Expression} objects which is evaluated
028 * on each exchange to compare them
029 *
030 * @version $Revision: 630591 $
031 */
032 public class ExpressionListComparator implements Comparator<Exchange> {
033 private final List<Expression> expressions;
034
035 public ExpressionListComparator(List<Expression> expressions) {
036 this.expressions = expressions;
037 }
038
039 public int compare(Exchange e1, Exchange e2) {
040 for (Expression expression : expressions) {
041 Object o1 = expression.evaluate(e1);
042 Object o2 = expression.evaluate(e2);
043 int answer = ObjectHelper.compare(o1, o2);
044 if (answer != 0) {
045 return answer;
046 }
047 }
048 return 0;
049 }
050 }