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 }