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.component.spring.integration;
018    
019    import org.apache.camel.Exchange;
020    import org.apache.camel.Processor;
021    import org.apache.camel.impl.DefaultConsumer;
022    import org.apache.camel.spring.SpringCamelContext;
023    import org.apache.camel.util.ObjectHelper;
024    import org.springframework.integration.MessageChannel;
025    import org.springframework.integration.core.MessageHandler;
026    import org.springframework.integration.core.SubscribableChannel;
027    import org.springframework.integration.support.channel.BeanFactoryChannelResolver;
028    import org.springframework.integration.support.channel.ChannelResolver;
029    
030    /**
031     * A consumer of exchanges for the Spring Integration
032     * Please specify the inputChannel in the endpoint url for this consumer.
033     * If the message pattern is inOut, the outputChannel property
034     * should be set for the outgoing message.
035     *
036     * @version 
037     */
038    public class SpringIntegrationConsumer  extends DefaultConsumer implements MessageHandler {
039        private final SpringCamelContext context;
040        private final ChannelResolver channelResolver;
041        private SubscribableChannel inputChannel;
042        private MessageChannel outputChannel;
043    
044        public SpringIntegrationConsumer(SpringIntegrationEndpoint endpoint, Processor processor) {
045            super(endpoint, processor);
046            this.context = (SpringCamelContext) endpoint.getCamelContext();
047            this.channelResolver = new BeanFactoryChannelResolver(context.getApplicationContext());
048        }
049    
050        @Override
051        public SpringIntegrationEndpoint getEndpoint() {
052            return (SpringIntegrationEndpoint) super.getEndpoint();
053        }
054    
055        protected void doStop() throws Exception {
056            inputChannel.unsubscribe(this);
057            super.doStop();
058        }
059    
060        protected void doStart() throws Exception {
061            super.doStart();
062    
063            if (getEndpoint().getMessageChannel() == null) {
064                String inputChannelName = getEndpoint().getDefaultChannel();
065                if (ObjectHelper.isEmpty(inputChannelName)) {
066                    inputChannelName = getEndpoint().getInputChannel();
067                }
068    
069                ObjectHelper.notEmpty(inputChannelName, "inputChannelName", getEndpoint());
070                inputChannel = (SubscribableChannel) channelResolver.resolveChannelName(inputChannelName);
071            } else {
072                inputChannel = (SubscribableChannel) getEndpoint().getMessageChannel();
073            }
074    
075            if (inputChannel == null) {
076                throw new IllegalArgumentException("Cannot resolve InputChannel on " + getEndpoint());
077            }
078    
079            // if we do in-out we need to setup the input channel as well
080            if (getEndpoint().isInOut()) {
081                // we need to setup right inputChannel for further processing
082                ObjectHelper.notEmpty(getEndpoint().getOutputChannel(), "OutputChannel", getEndpoint());
083                outputChannel = channelResolver.resolveChannelName(getEndpoint().getOutputChannel());
084    
085                if (outputChannel == null) {
086                    throw new IllegalArgumentException("Cannot resolve OutputChannel on " + getEndpoint());
087                }
088            }
089    
090            inputChannel.subscribe(this);
091        }
092        
093        public void handleMessage(org.springframework.integration.Message<?> siInMessage) {
094            // we received a message from spring integration
095            // wrap that in a Camel Exchange and process it
096            Exchange exchange = getEndpoint().createExchange();
097            exchange.setIn(new SpringIntegrationMessage(siInMessage));
098    
099            // process the exchange
100            try {
101                getProcessor().process(exchange);
102            } catch (Exception e) {
103                getExceptionHandler().handleException("Error processing exchange" , exchange, e);
104                return;
105            }
106    
107            // reply logic
108            if (getEndpoint().isInOut()) {
109                MessageChannel reply = null;
110    
111                // get the output channel from message header
112                Object returnAddress = siInMessage.getHeaders().getReplyChannel();
113                if (returnAddress != null) {
114                    if (returnAddress instanceof String) {
115                        reply = (MessageChannel) context.getApplicationContext().getBean((String)returnAddress);
116                    } else if (returnAddress instanceof MessageChannel) {
117                        reply = (MessageChannel) returnAddress;
118                    }
119                } else {
120                    reply = outputChannel;
121    
122                    // we want to do in-out so the inputChannel is mandatory (used to receive reply from spring integration)
123                    if (reply == null) {
124                        throw new IllegalArgumentException("OutputChannel has not been configured on " + getEndpoint());
125                    }
126                }
127    
128                if (reply == null) {
129                    throw new IllegalArgumentException("Cannot resolve ReplyChannel from message: " + siInMessage);
130                }
131    
132                // put the message back the outputChannel if we need
133                org.springframework.integration.Message siOutMessage =
134                    SpringIntegrationBinding.storeToSpringIntegrationMessage(exchange.getOut());
135    
136                // send the message to spring integration
137                if (log.isDebugEnabled()) {
138                    log.debug("Sending " + siOutMessage + " to ReplyChannel: " + reply);
139                }
140                reply.send(siOutMessage);
141            }        
142        }   
143    
144    }