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.AbstractCollection; 020 import java.util.Collection; 021 import java.util.Iterator; 022 import java.util.LinkedHashMap; 023 import java.util.Map; 024 025 import org.apache.camel.Exchange; 026 import org.apache.camel.Expression; 027 import org.apache.commons.logging.Log; 028 import org.apache.commons.logging.LogFactory; 029 030 /** 031 * A {@link Collection} which aggregates exchanges together using a correlation 032 * expression so that there is only a single message exchange sent for a single 033 * correlation key. 034 * 035 * @version $Revision: 53289 $ 036 */ 037 public class DefaultAggregationCollection extends AbstractCollection<Exchange> implements AggregationCollection { 038 039 private static final transient Log LOG = LogFactory.getLog(DefaultAggregationCollection.class); 040 private Expression<Exchange> correlationExpression; 041 private AggregationStrategy aggregationStrategy; 042 private Map<Object, Exchange> map = new LinkedHashMap<Object, Exchange>(); 043 044 public DefaultAggregationCollection() { 045 } 046 047 public DefaultAggregationCollection(Expression<Exchange> correlationExpression, AggregationStrategy aggregationStrategy) { 048 this.correlationExpression = correlationExpression; 049 this.aggregationStrategy = aggregationStrategy; 050 } 051 052 protected Map<Object, Exchange> getMap() { 053 return map; 054 } 055 056 @Override 057 public boolean add(Exchange exchange) { 058 Object correlationKey = correlationExpression.evaluate(exchange); 059 Exchange oldExchange = map.get(correlationKey); 060 Exchange newExchange = exchange; 061 062 if (oldExchange != null) { 063 Integer count = oldExchange.getProperty(Exchange.AGGREGATED_COUNT, Integer.class); 064 if (count == null) { 065 count = 1; 066 } 067 count++; 068 newExchange = aggregationStrategy.aggregate(oldExchange, newExchange); 069 newExchange.setProperty(Exchange.AGGREGATED_COUNT, count); 070 } 071 072 // the strategy may just update the old exchange and return it 073 if (newExchange != oldExchange) { 074 if (LOG.isDebugEnabled()) { 075 LOG.debug("put exchange:" + newExchange + " for key:" + correlationKey); 076 } 077 if (oldExchange == null) { 078 newExchange.setProperty(Exchange.AGGREGATED_COUNT, Integer.valueOf(1)); 079 } 080 map.put(correlationKey, newExchange); 081 } 082 083 onAggregation(correlationKey, newExchange); 084 085 return true; 086 } 087 088 public Iterator<Exchange> iterator() { 089 return map.values().iterator(); 090 } 091 092 public int size() { 093 return map.size(); 094 } 095 096 @Override 097 public void clear() { 098 map.clear(); 099 } 100 101 public void onAggregation(Object correlationKey, Exchange newExchange) { 102 } 103 104 public Expression<Exchange> getCorrelationExpression() { 105 return correlationExpression; 106 } 107 108 public void setCorrelationExpression(Expression<Exchange> correlationExpression) { 109 this.correlationExpression = correlationExpression; 110 } 111 112 public AggregationStrategy getAggregationStrategy() { 113 return aggregationStrategy; 114 } 115 116 public void setAggregationStrategy(AggregationStrategy aggregationStrategy) { 117 this.aggregationStrategy = aggregationStrategy; 118 } 119 }