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 org.apache.camel.AsyncCallback;
020 import org.apache.camel.AsyncProcessor;
021 import org.apache.camel.Exchange;
022 import org.apache.camel.impl.DefaultUnitOfWork;
023 import static org.apache.camel.util.ObjectHelper.wrapRuntimeCamelException;
024
025 /**
026 * Handles calling the UnitOfWork.done() method when processing of an exchange
027 * is complete.
028 */
029 public final class UnitOfWorkProcessor extends DelegateAsyncProcessor {
030
031 public UnitOfWorkProcessor(AsyncProcessor processor) {
032 super(processor);
033 }
034
035 @Override
036 public String toString() {
037 return "UnitOfWork(" + processor + ")";
038 }
039
040 public boolean process(final Exchange exchange, final AsyncCallback callback) {
041 if (exchange.getUnitOfWork() == null) {
042 // If there is no existing UoW, then we should start one and
043 // terminate it once processing is completed for the exchange.
044 final DefaultUnitOfWork uow = new DefaultUnitOfWork();
045 exchange.setUnitOfWork(uow);
046 try {
047 uow.start();
048 } catch (Exception e) {
049 throw wrapRuntimeCamelException(e);
050 }
051 // return the process code where we do stop and cleanup
052 return processor.process(exchange, new AsyncCallback() {
053 public void done(boolean sync) {
054 // Order here matters. We need to complete the callbacks
055 // since they will likely update the exchange with
056 // some final results.
057 callback.done(sync);
058 exchange.getUnitOfWork().done(exchange);
059 try {
060 uow.stop();
061 } catch (Exception e) {
062 throw wrapRuntimeCamelException(e);
063 }
064 exchange.setUnitOfWork(null);
065 }
066 });
067 } else {
068 // There was an existing UoW, so we should just pass through..
069 // so that the guy the initiated the UoW can terminate it.
070 return processor.process(exchange, callback);
071 }
072 }
073
074 }