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.util;
018
019import java.util.Comparator;
020
021import org.apache.camel.Exchange;
022import org.apache.camel.Expression;
023
024/**
025 * An implementation of {@link Comparator} that takes an {@link Expression} which is evaluated
026 * on each exchange to be compared
027 *  
028 * @version 
029 */
030public 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, Object.class);
039        Object o2 = expression.evaluate(e2, Object.class);
040        return ObjectHelper.compare(o1, o2);
041    }
042}