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
025 /**
026 * An implementation of {@link Comparator} which takes an {@link Expression} which is evaluated
027 * on each exchange to compare
028 *
029 * @version $Revision: 1.1 $
030 */
031 public class ExpressionComparator<E extends Exchange> implements Comparator<E> {
032 private final Expression<E> expression;
033
034 public ExpressionComparator(Expression<E> expression) {
035 this.expression = expression;
036 }
037
038 public int compare(E e1, E e2) {
039 Object o1 = expression.evaluate(e1);
040 Object o2 = expression.evaluate(e2);
041 return ObjectHelper.compare(o1, o2);
042 }
043 }