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.example;
018    
019    import org.apache.camel.Exchange;
020    import org.apache.camel.processor.aggregate.AggregationStrategy;
021    
022    /**
023     * Aggregate two numbers
024     *
025     * @version $Revision: 18163 $
026     */
027    // START SNIPPET: e1
028    public class NumberAggregationStrategy implements AggregationStrategy {
029    
030        public Exchange aggregate(Exchange oldExchange, Exchange newExchange) {
031            if (oldExchange == null) {
032                return newExchange;
033            }
034    
035            Integer num1 = oldExchange.getIn().getBody(Integer.class);
036            Integer num2 = newExchange.getIn().getBody(Integer.class);
037    
038            // just avoid bad inputs by assuming its a 0 value
039            Integer num3 = (num1 != null ? num1 : 0) + (num2 != null ? num2 : 0);
040            oldExchange.getIn().setBody(num3);
041    
042            return oldExchange;
043        }
044    
045    }
046    // END SNIPPET: e1