| /** |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.camel.processor.aggregate; |
| |
| import java.util.AbstractCollection; |
| import java.util.Iterator; |
| import java.util.LinkedHashMap; |
| import java.util.Map; |
| import java.util.concurrent.atomic.AtomicInteger; |
| |
| import org.apache.camel.Exchange; |
| import org.apache.camel.Expression; |
| import org.apache.camel.util.ObjectHelper; |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| |
| /** |
| * A {@link java.util.Collection} which aggregates exchanges together using a correlation |
| * expression so that there is only a single message exchange sent for a single |
| * correlation key. |
| * |
| * @version $Revision$ |
| */ |
| public class DefaultAggregationCollection extends AbstractCollection<Exchange> implements AggregationCollection { |
| |
| private static final transient Log LOG = LogFactory.getLog(DefaultAggregationCollection.class); |
| private Expression correlationExpression; |
| private AggregationStrategy aggregationStrategy; |
| private final Map<Object, Exchange> aggregated = new LinkedHashMap<Object, Exchange>(); |
| private final AtomicInteger counter = new AtomicInteger(); |
| |
| public DefaultAggregationCollection() { |
| } |
| |
| public DefaultAggregationCollection(Expression correlationExpression, AggregationStrategy aggregationStrategy) { |
| this.correlationExpression = correlationExpression; |
| this.aggregationStrategy = aggregationStrategy; |
| } |
| |
| protected Map<Object, Exchange> getAggregated() { |
| return aggregated; |
| } |
| |
| @Override |
| public boolean add(Exchange exchange) { |
| // do not add exchange if it was filtered |
| Boolean filtered = exchange.getProperty(Exchange.FILTERED, Boolean.class); |
| if (filtered != null && filtered) { |
| if (LOG.isTraceEnabled()) { |
| LOG.trace("Cannot aggregate exchange as its filtered: " + exchange); |
| } |
| return false; |
| } |
| |
| Object correlationKey = correlationExpression.evaluate(exchange, Object.class); |
| if (LOG.isTraceEnabled()) { |
| LOG.trace("Evaluated expression: " + correlationExpression + " as correlation key: " + correlationKey); |
| } |
| |
| // TODO: correlationKey evalutated to null should be skipped by default |
| |
| Exchange oldExchange = aggregated.get(correlationKey); |
| Exchange newExchange = exchange; |
| |
| Integer size = 1; |
| if (oldExchange != null) { |
| size = oldExchange.getProperty(Exchange.AGGREGATED_SIZE, Integer.class); |
| ObjectHelper.notNull(size, Exchange.AGGREGATED_SIZE + " on " + oldExchange); |
| size++; |
| } |
| newExchange = aggregationStrategy.aggregate(oldExchange, newExchange); |
| newExchange.setProperty(Exchange.AGGREGATED_SIZE, size); |
| |
| // update the index counter |
| newExchange.setProperty(Exchange.AGGREGATED_INDEX, counter.getAndIncrement()); |
| |
| // the strategy may just update the old exchange and return it |
| if (!newExchange.equals(oldExchange)) { |
| if (LOG.isTraceEnabled()) { |
| LOG.trace("Put exchange:" + newExchange + " with correlation key:" + correlationKey); |
| } |
| aggregated.put(correlationKey, newExchange); |
| } |
| |
| onAggregation(correlationKey, newExchange); |
| |
| return true; |
| } |
| |
| public Iterator<Exchange> iterator() { |
| return aggregated.values().iterator(); |
| } |
| |
| public int size() { |
| return aggregated.size(); |
| } |
| |
| @Override |
| public void clear() { |
| aggregated.clear(); |
| counter.set(0); |
| } |
| |
| public void onAggregation(Object correlationKey, Exchange exchange) { |
| } |
| |
| public Expression getCorrelationExpression() { |
| return correlationExpression; |
| } |
| |
| public void setCorrelationExpression(Expression correlationExpression) { |
| this.correlationExpression = correlationExpression; |
| } |
| |
| public AggregationStrategy getAggregationStrategy() { |
| return aggregationStrategy; |
| } |
| |
| public void setAggregationStrategy(AggregationStrategy aggregationStrategy) { |
| this.aggregationStrategy = aggregationStrategy; |
| } |
| } |