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;
018
019 import java.io.Closeable;
020 import java.util.ArrayList;
021 import java.util.Collection;
022 import java.util.Collections;
023 import java.util.Iterator;
024 import java.util.List;
025 import java.util.Scanner;
026 import java.util.concurrent.ExecutorService;
027
028 import org.apache.camel.AsyncCallback;
029 import org.apache.camel.AsyncProcessor;
030 import org.apache.camel.CamelContext;
031 import org.apache.camel.Exchange;
032 import org.apache.camel.Expression;
033 import org.apache.camel.Message;
034 import org.apache.camel.Processor;
035 import org.apache.camel.processor.aggregate.AggregationStrategy;
036 import org.apache.camel.processor.aggregate.UseOriginalAggregationStrategy;
037 import org.apache.camel.util.CollectionHelper;
038 import org.apache.camel.util.IOHelper;
039 import org.apache.camel.util.ObjectHelper;
040 import org.apache.commons.logging.Log;
041 import org.apache.commons.logging.LogFactory;
042
043 import static org.apache.camel.util.ObjectHelper.notNull;
044
045 /**
046 * Implements a dynamic <a
047 * href="http://camel.apache.org/splitter.html">Splitter</a> pattern
048 * where an expression is evaluated to iterate through each of the parts of a
049 * message and then each part is then send to some endpoint.
050 *
051 * @version $Revision: 20167 $
052 */
053 public class Splitter extends MulticastProcessor implements AsyncProcessor, Traceable {
054 private static final transient Log LOG = LogFactory.getLog(Splitter.class);
055
056 private final Expression expression;
057
058 public Splitter(CamelContext camelContext, Expression expression, Processor destination, AggregationStrategy aggregationStrategy) {
059 this(camelContext, expression, destination, aggregationStrategy, false, null, false, false);
060 }
061
062 public Splitter(CamelContext camelContext, Expression expression, Processor destination, AggregationStrategy aggregationStrategy,
063 boolean parallelProcessing, ExecutorService executorService, boolean streaming, boolean stopOnException) {
064 super(camelContext, Collections.singleton(destination), aggregationStrategy, parallelProcessing, executorService, streaming, stopOnException);
065
066 this.expression = expression;
067 notNull(expression, "expression");
068 notNull(destination, "destination");
069 }
070
071 @Override
072 public String toString() {
073 return "Splitter[on: " + expression + " to: " + getProcessors().iterator().next() + " aggregate: " + getAggregationStrategy() + "]";
074 }
075
076 @Override
077 public String getTraceLabel() {
078 return "split[" + expression + "]";
079 }
080
081 @Override
082 public boolean process(Exchange exchange, final AsyncCallback callback) {
083 final AggregationStrategy strategy = getAggregationStrategy();
084
085 // if no custom aggregation strategy is being used then fallback to keep the original
086 // and propagate exceptions which is done by a per exchange specific aggregation strategy
087 // to ensure it supports async routing
088 if (strategy == null) {
089 UseOriginalAggregationStrategy original = new UseOriginalAggregationStrategy(exchange, true);
090 exchange.setProperty(Exchange.AGGREGATION_STRATEGY, original);
091 }
092
093 return super.process(exchange, callback);
094 }
095
096 @Override
097 protected Iterable<ProcessorExchangePair> createProcessorExchangePairs(Exchange exchange) {
098 Object value = expression.evaluate(exchange, Object.class);
099
100 if (isStreaming()) {
101 return createProcessorExchangePairsIterable(exchange, value);
102 } else {
103 return createProcessorExchangePairsList(exchange, value);
104 }
105 }
106
107 @SuppressWarnings("unchecked")
108 private Iterable<ProcessorExchangePair> createProcessorExchangePairsIterable(final Exchange exchange, final Object value) {
109 final Iterator iterator = ObjectHelper.createIterator(value);
110 return new Iterable() {
111
112 public Iterator iterator() {
113 return new Iterator() {
114 private int index;
115 private boolean closed;
116
117 public boolean hasNext() {
118 if (closed) {
119 return false;
120 }
121
122 boolean answer = iterator.hasNext();
123 if (!answer) {
124 // we are now closed
125 closed = true;
126 // nothing more so we need to close the expression value in case it needs to be
127 if (value instanceof Closeable) {
128 IOHelper.close((Closeable) value, value.getClass().getName(), LOG);
129 } else if (value instanceof Scanner) {
130 // special for Scanner as it does not implement Closeable
131 ((Scanner) value).close();
132 }
133 }
134 return answer;
135 }
136
137 public Object next() {
138 Object part = iterator.next();
139 Exchange newExchange = exchange.copy();
140 if (part instanceof Message) {
141 newExchange.setIn((Message)part);
142 } else {
143 Message in = newExchange.getIn();
144 in.setBody(part);
145 }
146 return createProcessorExchangePair(index++, getProcessors().iterator().next(), newExchange);
147 }
148
149 public void remove() {
150 throw new UnsupportedOperationException("Remove is not supported by this iterator");
151 }
152 };
153 }
154
155 };
156 }
157
158 private Iterable<ProcessorExchangePair> createProcessorExchangePairsList(Exchange exchange, Object value) {
159 List<ProcessorExchangePair> result;
160 Integer collectionSize = CollectionHelper.size(value);
161 if (collectionSize != null) {
162 result = new ArrayList<ProcessorExchangePair>(collectionSize);
163 } else {
164 result = new ArrayList<ProcessorExchangePair>();
165 }
166
167 int index = 0;
168 Iterator<Object> iter = ObjectHelper.createIterator(value);
169 while (iter.hasNext()) {
170 Object part = iter.next();
171 Exchange newExchange = exchange.copy();
172 if (part instanceof Message) {
173 newExchange.setIn((Message)part);
174 } else {
175 Message in = newExchange.getIn();
176 in.setBody(part);
177 }
178 result.add(createProcessorExchangePair(index++, getProcessors().iterator().next(), newExchange));
179 }
180 return result;
181 }
182
183 @Override
184 protected void updateNewExchange(Exchange exchange, int index, Iterable<ProcessorExchangePair> allPairs,
185 Iterator<ProcessorExchangePair> it) {
186 exchange.setProperty(Exchange.SPLIT_INDEX, index);
187 if (allPairs instanceof Collection) {
188 exchange.setProperty(Exchange.SPLIT_SIZE, ((Collection<?>)allPairs).size());
189 }
190 if (it.hasNext()) {
191 exchange.setProperty(Exchange.SPLIT_COMPLETE, Boolean.FALSE);
192 } else {
193 exchange.setProperty(Exchange.SPLIT_COMPLETE, Boolean.TRUE);
194 }
195 }
196
197 public Expression getExpression() {
198 return expression;
199 }
200 }