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.processor.aggregate;
018    
019    import java.util.ArrayList;
020    import java.util.List;
021    
022    import org.apache.camel.Exchange;
023    import org.apache.camel.impl.DefaultExchange;
024    
025    /**
026     * Aggregate all exchanges into a single combined Exchange holding all the aggregated exchanges
027     * in a {@link java.util.List} as a exchange property with the key
028     * {@link org.apache.camel.Exchange#GROUPED_EXCHANGE}.
029     *
030     * @version $Revision: 885364 $
031     */
032    public class GroupedExchangeAggregationStrategy implements AggregationStrategy {
033    
034        @SuppressWarnings("unchecked")
035        public Exchange aggregate(Exchange oldExchange, Exchange newExchange) {
036            List<Exchange> list;
037            Exchange answer = oldExchange;
038    
039            if (oldExchange == null) {
040                answer = new DefaultExchange(newExchange);
041                list = new ArrayList<Exchange>();
042                answer.setProperty(Exchange.GROUPED_EXCHANGE, list);
043            } else {
044                list = oldExchange.getProperty(Exchange.GROUPED_EXCHANGE, List.class);
045            }
046    
047            if (newExchange != null) {
048                list.add(newExchange);
049            }
050            return answer;
051        }
052    
053    }
054