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.Collection; 020 import java.util.Iterator; 021 022 import org.apache.camel.Endpoint; 023 import org.apache.camel.Exchange; 024 import org.apache.camel.PollingConsumer; 025 import org.apache.camel.Processor; 026 import org.apache.camel.impl.LoggingExceptionHandler; 027 import org.apache.camel.impl.ServiceSupport; 028 import org.apache.camel.spi.ExceptionHandler; 029 import org.apache.camel.util.ServiceHelper; 030 import org.apache.commons.logging.Log; 031 import org.apache.commons.logging.LogFactory; 032 033 /** 034 * A base class for any kind of {@link Processor} which implements some kind of 035 * batch processing. 036 * 037 * @version $Revision: 1.1 $ 038 */ 039 public class BatchProcessor extends ServiceSupport implements Runnable { 040 private static final transient Log LOG = LogFactory.getLog(Resequencer.class); 041 private Endpoint endpoint; 042 private Processor processor; 043 private Collection<Exchange> collection; 044 private long batchTimeout = 1000L; 045 private int batchSize = 100; 046 private PollingConsumer consumer; 047 private ExceptionHandler exceptionHandler; 048 049 public BatchProcessor(Endpoint endpoint, Processor processor, Collection<Exchange> collection) { 050 this.endpoint = endpoint; 051 this.processor = processor; 052 this.collection = collection; 053 } 054 055 @Override 056 public String toString() { 057 return "BatchProcessor[to: " + processor + "]"; 058 } 059 060 public void run() { 061 LOG.debug("Starting thread for " + this); 062 while (!isStopped() && !isStopping()) { 063 try { 064 processBatch(); 065 } catch (Exception e) { 066 getExceptionHandler().handleException(e); 067 } 068 } 069 collection.clear(); 070 } 071 072 // Properties 073 // ------------------------------------------------------------------------- 074 public ExceptionHandler getExceptionHandler() { 075 if (exceptionHandler == null) { 076 exceptionHandler = new LoggingExceptionHandler(getClass()); 077 } 078 return exceptionHandler; 079 } 080 081 public void setExceptionHandler(ExceptionHandler exceptionHandler) { 082 this.exceptionHandler = exceptionHandler; 083 } 084 085 public int getBatchSize() { 086 return batchSize; 087 } 088 089 public void setBatchSize(int batchSize) { 090 this.batchSize = batchSize; 091 } 092 093 public long getBatchTimeout() { 094 return batchTimeout; 095 } 096 097 public void setBatchTimeout(long batchTimeout) { 098 this.batchTimeout = batchTimeout; 099 } 100 101 public Endpoint getEndpoint() { 102 return endpoint; 103 } 104 105 public Processor getProcessor() { 106 return processor; 107 } 108 109 /** 110 * A transactional method to process a batch of messages up to a timeout 111 * period or number of messages reached. 112 */ 113 protected synchronized void processBatch() throws Exception { 114 long start = System.currentTimeMillis(); 115 long end = start + batchTimeout; 116 for (int i = 0; i < batchSize; i++) { 117 long timeout = end - System.currentTimeMillis(); 118 119 Exchange exchange = consumer.receive(timeout); 120 if (exchange == null) { 121 break; 122 } 123 collection.add(exchange); 124 } 125 126 if (LOG.isDebugEnabled()) { 127 LOG.debug("Finsihed batch size: " + batchSize + " timeout: " + batchTimeout + " so sending set: " 128 + collection); 129 } 130 131 // lets send the batch 132 Iterator<Exchange> iter = collection.iterator(); 133 while (iter.hasNext()) { 134 Exchange exchange = iter.next(); 135 iter.remove(); 136 processExchange(exchange); 137 } 138 } 139 140 /** 141 * Strategy Method to process an exchange in the batch. This method allows 142 * derived classes to perform custom processing before or after an 143 * individual exchange is processed 144 */ 145 protected void processExchange(Exchange exchange) throws Exception { 146 processor.process(exchange); 147 } 148 149 protected void doStart() throws Exception { 150 consumer = endpoint.createPollingConsumer(); 151 152 ServiceHelper.startServices(processor, consumer); 153 154 Thread thread = new Thread(this, this + " Polling Thread"); 155 thread.start(); 156 } 157 158 protected void doStop() throws Exception { 159 ServiceHelper.stopServices(consumer, processor); 160 collection.clear(); 161 } 162 163 protected Collection<Exchange> getCollection() { 164 return collection; 165 } 166 }