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.util.concurrent.Callable;
020 import java.util.concurrent.ExecutorService;
021
022 import org.apache.camel.CamelContext;
023 import org.apache.camel.Exchange;
024 import org.apache.camel.ExchangePattern;
025 import org.apache.camel.Message;
026 import org.apache.camel.Ordered;
027 import org.apache.camel.Predicate;
028 import org.apache.camel.Processor;
029 import org.apache.camel.Traceable;
030 import org.apache.camel.support.ServiceSupport;
031 import org.apache.camel.support.SynchronizationAdapter;
032 import org.apache.camel.util.ExchangeHelper;
033 import org.apache.camel.util.ServiceHelper;
034 import org.slf4j.Logger;
035 import org.slf4j.LoggerFactory;
036
037 import static org.apache.camel.util.ObjectHelper.notNull;
038
039 /**
040 * @version
041 */
042 public class OnCompletionProcessor extends ServiceSupport implements Processor, Traceable {
043
044 private static final transient Logger LOG = LoggerFactory.getLogger(OnCompletionProcessor.class);
045 private final CamelContext camelContext;
046 private final Processor processor;
047 private final ExecutorService executorService;
048 private final boolean shutdownExecutorService;
049 private final boolean onCompleteOnly;
050 private final boolean onFailureOnly;
051 private final Predicate onWhen;
052 private final boolean useOriginalBody;
053
054 public OnCompletionProcessor(CamelContext camelContext, Processor processor, ExecutorService executorService, boolean shutdownExecutorService,
055 boolean onCompleteOnly, boolean onFailureOnly, Predicate onWhen, boolean useOriginalBody) {
056 notNull(camelContext, "camelContext");
057 notNull(processor, "processor");
058 this.camelContext = camelContext;
059 // wrap processor in UnitOfWork so what we send out runs in a UoW
060 this.processor = new UnitOfWorkProcessor(processor);
061 this.executorService = executorService;
062 this.shutdownExecutorService = shutdownExecutorService;
063 this.onCompleteOnly = onCompleteOnly;
064 this.onFailureOnly = onFailureOnly;
065 this.onWhen = onWhen;
066 this.useOriginalBody = useOriginalBody;
067 }
068
069 @Override
070 protected void doStart() throws Exception {
071 ServiceHelper.startService(processor);
072 }
073
074 @Override
075 protected void doStop() throws Exception {
076 ServiceHelper.stopService(processor);
077 }
078
079 @Override
080 protected void doShutdown() throws Exception {
081 ServiceHelper.stopAndShutdownService(processor);
082 if (shutdownExecutorService) {
083 getCamelContext().getExecutorServiceManager().shutdownNow(executorService);
084 }
085 }
086
087 public CamelContext getCamelContext() {
088 return camelContext;
089 }
090
091 public void process(Exchange exchange) throws Exception {
092 if (processor == null) {
093 return;
094 }
095
096 // register callback
097 exchange.getUnitOfWork().addSynchronization(new OnCompletionSynchronization());
098 }
099
100 /**
101 * Processes the exchange by the processors
102 *
103 * @param processor the processor
104 * @param exchange the exchange
105 */
106 protected static void doProcess(Processor processor, Exchange exchange) {
107 try {
108 processor.process(exchange);
109 } catch (Exception e) {
110 exchange.setException(e);
111 }
112 }
113
114 /**
115 * Prepares the {@link Exchange} to send as onCompletion.
116 *
117 * @param exchange the current exchange
118 * @return the exchange to be routed in onComplete
119 */
120 protected Exchange prepareExchange(Exchange exchange) {
121 Exchange answer;
122
123 // for asynchronous routing we must use a copy as we dont want it
124 // to cause side effects of the original exchange
125 // (the original thread will run in parallel)
126 answer = ExchangeHelper.createCorrelatedCopy(exchange, false);
127 if (answer.hasOut()) {
128 // move OUT to IN (pipes and filters)
129 answer.setIn(answer.getOut());
130 answer.setOut(null);
131 }
132 // set MEP to InOnly as this wire tap is a fire and forget
133 answer.setPattern(ExchangePattern.InOnly);
134
135 if (useOriginalBody) {
136 LOG.trace("Using the original IN message instead of current");
137
138 Message original = exchange.getUnitOfWork().getOriginalInMessage();
139 answer.setIn(original);
140 }
141
142 // add a header flag to indicate its a on completion exchange
143 answer.setProperty(Exchange.ON_COMPLETION, Boolean.TRUE);
144
145 return answer;
146 }
147
148 private final class OnCompletionSynchronization extends SynchronizationAdapter implements Ordered {
149
150 public int getOrder() {
151 // we want to be last
152 return Ordered.LOWEST;
153 }
154
155 @Override
156 public void onComplete(final Exchange exchange) {
157 if (onFailureOnly) {
158 return;
159 }
160
161 if (onWhen != null && !onWhen.matches(exchange)) {
162 // predicate did not match so do not route the onComplete
163 return;
164 }
165
166 // must use a copy as we dont want it to cause side effects of the original exchange
167 final Exchange copy = prepareExchange(exchange);
168
169 executorService.submit(new Callable<Exchange>() {
170 public Exchange call() throws Exception {
171 LOG.debug("Processing onComplete: {}", copy);
172 doProcess(processor, copy);
173 return copy;
174 }
175 });
176 }
177
178 public void onFailure(final Exchange exchange) {
179 if (onCompleteOnly) {
180 return;
181 }
182
183 if (onWhen != null && !onWhen.matches(exchange)) {
184 // predicate did not match so do not route the onComplete
185 return;
186 }
187
188 // must use a copy as we dont want it to cause side effects of the original exchange
189 final Exchange copy = prepareExchange(exchange);
190 // must remove exception otherwise onFailure routing will fail as well
191 // the caused exception is stored as a property (Exchange.EXCEPTION_CAUGHT) on the exchange
192 copy.setException(null);
193
194 executorService.submit(new Callable<Exchange>() {
195 public Exchange call() throws Exception {
196 LOG.debug("Processing onFailure: {}", copy);
197 doProcess(processor, copy);
198 return null;
199 }
200 });
201 }
202
203 @Override
204 public String toString() {
205 if (!onCompleteOnly && !onFailureOnly) {
206 return "onCompleteOrFailure";
207 } else if (onCompleteOnly) {
208 return "onCompleteOnly";
209 } else {
210 return "onFailureOnly";
211 }
212 }
213 }
214
215 @Override
216 public String toString() {
217 return "OnCompletionProcessor[" + processor + "]";
218 }
219
220 public String getTraceLabel() {
221 return "onCompletion";
222 }
223 }