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
021 import org.apache.camel.Exchange;
022 import org.apache.camel.Expression;
023
024 /**
025 * An implementation of {@link Comparator} which takes an {@link Expression} which is evaluated
026 * on each exchange to compare
027 *
028 * @version $Revision: 709613 $
029 */
030 public class ExpressionComparator implements Comparator<Exchange> {
031 private final Expression expression;
032
033 public ExpressionComparator(Expression expression) {
034 this.expression = expression;
035 }
036
037 public int compare(Exchange e1, Exchange e2) {
038 Object o1 = expression.evaluate(e1);
039 Object o2 = expression.evaluate(e2);
040 return ObjectHelper.compare(o1, o2);
041 }
042 }