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.direct;
018
019 import java.util.concurrent.CopyOnWriteArrayList;
020
021 import org.apache.camel.Consumer;
022 import org.apache.camel.Exchange;
023 import org.apache.camel.Processor;
024 import org.apache.camel.Producer;
025 import org.apache.camel.impl.DefaultConsumer;
026 import org.apache.camel.impl.DefaultEndpoint;
027 import org.apache.camel.impl.DefaultExchange;
028 import org.apache.camel.impl.DefaultProducer;
029 import org.apache.camel.util.ProducerCache;
030 import org.apache.commons.logging.Log;
031 import org.apache.commons.logging.LogFactory;
032
033 /**
034 * Represents a direct endpoint that synchronously invokes the consumers of the endpoint when a producer
035 * sends a message to it.
036 *
037 * @org.apache.xbean.XBean
038 * @version $Revision: 519973 $
039 */
040 public class DirectEndpoint<E extends Exchange> extends DefaultEndpoint<E> {
041 private static final Log log = LogFactory.getLog(DirectEndpoint.class);
042
043 private final CopyOnWriteArrayList<DefaultConsumer<E>> consumers = new CopyOnWriteArrayList<DefaultConsumer<E>>();
044
045 boolean allowMultipleConsumers=true;
046
047 public DirectEndpoint(String uri, DirectComponent<E> component) {
048 super(uri, component);
049 }
050
051 public Producer createProducer() throws Exception {
052 return new DefaultProducer(this) {
053 public void process(Exchange exchange) throws Exception {
054 DirectEndpoint.this.process(exchange);
055 }
056 };
057 }
058
059 protected void process(Exchange exchange) throws Exception {
060 if (consumers.isEmpty()) {
061 log.warn("No consumers available on " + this + " for " + exchange);
062 }
063 else {
064 for (DefaultConsumer<E> consumer : consumers) {
065 consumer.getProcessor().process(exchange);
066 }
067 }
068 }
069
070 public Consumer<E> createConsumer(Processor processor) throws Exception {
071 return new DefaultConsumer<E>(this, processor) {
072 @Override
073 public void start() throws Exception {
074 if( !allowMultipleConsumers && !consumers.isEmpty() )
075 throw new IllegalStateException("Endpoint "+getEndpointUri()+" only allows 1 active consumer but you attempted to start a 2nd consumer.");
076
077 consumers.add(this);
078 super.start();
079 }
080
081 @Override
082 public void stop() throws Exception {
083 super.stop();
084 consumers.remove(this);
085 }
086 };
087 }
088
089 public E createExchange() {
090 // How can we create a specific Exchange if we are generic??
091 // perhaps it would be better if we did not implement this.
092 return (E) new DefaultExchange(getContext());
093 }
094
095 public boolean isAllowMultipleConsumers() {
096 return allowMultipleConsumers;
097 }
098 public void setAllowMultipleConsumers(boolean allowMutlipleConsumers) {
099 this.allowMultipleConsumers = allowMutlipleConsumers;
100 }
101
102 public boolean isSingleton() {
103 return true;
104 }
105
106 }