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: 35332 $ 038 */ 039 public class BatchProcessor extends ServiceSupport implements Runnable { 040 public static final long DEFAULT_BATCH_TIMEOUT = 1000L; 041 public static final int DEFAULT_BATCH_SIZE = 100; 042 043 private static final transient Log LOG = LogFactory.getLog(BatchProcessor.class); 044 private Endpoint endpoint; 045 private Processor processor; 046 private Collection<Exchange> collection; 047 private long batchTimeout = DEFAULT_BATCH_TIMEOUT; 048 private int batchSize = DEFAULT_BATCH_SIZE; 049 private PollingConsumer consumer; 050 private ExceptionHandler exceptionHandler; 051 052 public BatchProcessor(Endpoint endpoint, Processor processor, Collection<Exchange> collection) { 053 this.endpoint = endpoint; 054 this.processor = processor; 055 this.collection = collection; 056 } 057 058 @Override 059 public String toString() { 060 return "BatchProcessor[to: " + processor + "]"; 061 } 062 063 public void run() { 064 LOG.debug("Starting thread for " + this); 065 while (isRunAllowed()) { 066 try { 067 processBatch(); 068 } catch (Exception e) { 069 getExceptionHandler().handleException(e); 070 } 071 } 072 collection.clear(); 073 } 074 075 // Properties 076 // ------------------------------------------------------------------------- 077 public ExceptionHandler getExceptionHandler() { 078 if (exceptionHandler == null) { 079 exceptionHandler = new LoggingExceptionHandler(getClass()); 080 } 081 return exceptionHandler; 082 } 083 084 public void setExceptionHandler(ExceptionHandler exceptionHandler) { 085 this.exceptionHandler = exceptionHandler; 086 } 087 088 public int getBatchSize() { 089 return batchSize; 090 } 091 092 public void setBatchSize(int batchSize) { 093 this.batchSize = batchSize; 094 } 095 096 public long getBatchTimeout() { 097 return batchTimeout; 098 } 099 100 public void setBatchTimeout(long batchTimeout) { 101 this.batchTimeout = batchTimeout; 102 } 103 104 public Endpoint getEndpoint() { 105 return endpoint; 106 } 107 108 public Processor getProcessor() { 109 return processor; 110 } 111 112 /** 113 * A transactional method to process a batch of messages up to a timeout 114 * period or number of messages reached. 115 */ 116 protected synchronized void processBatch() throws Exception { 117 long start = System.currentTimeMillis(); 118 long end = start + batchTimeout; 119 for (int i = 0; !isBatchCompleted(i); i++) { 120 long timeout = end - System.currentTimeMillis(); 121 if (timeout < 0L) { 122 LOG.debug("batch timeout expired at batch index:" + i); 123 break; 124 } 125 Exchange exchange = consumer.receive(timeout); 126 if (exchange == null) { 127 LOG.debug("receive with timeout: " + timeout + " expired at batch index:" + i); 128 break; 129 } 130 collection.add(exchange); 131 } 132 133 if (LOG.isDebugEnabled()) { 134 LOG.debug("Finished batch size: " + batchSize + " timeout: " + batchTimeout + " so sending set: " 135 + collection); 136 } 137 138 // lets send the batch 139 Iterator<Exchange> iter = collection.iterator(); 140 while (iter.hasNext()) { 141 Exchange exchange = iter.next(); 142 iter.remove(); 143 processExchange(exchange); 144 } 145 } 146 147 /** 148 * A strategy method to decide if the batch is completed the resulting exchanges should be sent 149 */ 150 protected boolean isBatchCompleted(int index) { 151 return index >= batchSize; 152 } 153 154 /** 155 * Strategy Method to process an exchange in the batch. This method allows 156 * derived classes to perform custom processing before or after an 157 * individual exchange is processed 158 */ 159 protected void processExchange(Exchange exchange) throws Exception { 160 processor.process(exchange); 161 } 162 163 protected void doStart() throws Exception { 164 consumer = endpoint.createPollingConsumer(); 165 166 ServiceHelper.startServices(processor, consumer); 167 168 Thread thread = new Thread(this, this + " Polling Thread"); 169 thread.start(); 170 } 171 172 protected void doStop() throws Exception { 173 ServiceHelper.stopServices(consumer, processor); 174 collection.clear(); 175 } 176 177 protected Collection<Exchange> getCollection() { 178 return collection; 179 } 180 }