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 org.apache.camel.Exchange;
020 import org.apache.camel.Expression;
021 import org.apache.camel.Processor;
022 import org.apache.camel.util.ExchangeHelper;
023 import org.apache.commons.logging.Log;
024 import org.apache.commons.logging.LogFactory;
025
026 /**
027 * The processor which sends messages in a loop.
028 *
029 * @version $Revision: 788621 $
030 */
031 public class LoopProcessor extends DelegateProcessor implements Traceable {
032 private static final Log LOG = LogFactory.getLog(LoopProcessor.class);
033
034 private final Expression expression;
035
036 public LoopProcessor(Expression expression, Processor processor) {
037 super(processor);
038 this.expression = expression;
039 }
040
041 @Override
042 public void process(Exchange exchange) throws Exception {
043 // Intermediate conversion to String is needed when direct conversion to Integer is not available
044 // but evaluation result is a textual representation of a numeric value.
045 String text = expression.evaluate(exchange, String.class);
046 int count = ExchangeHelper.convertToMandatoryType(exchange, Integer.class, text);
047
048 exchange.setProperty(Exchange.LOOP_SIZE, count);
049 for (int i = 0; i < count; i++) {
050 if (LOG.isDebugEnabled()) {
051 LOG.debug("LoopProcessor: iteration #" + i);
052 }
053 exchange.setProperty(Exchange.LOOP_INDEX, i);
054 super.process(exchange);
055 }
056 }
057
058 @Override
059 public String toString() {
060 return "Loop[for: " + expression + " times do: " + getProcessor() + "]";
061 }
062
063 public String getTraceLabel() {
064 return "Loop[" + expression + "]";
065 }
066
067 public Expression getExpression() {
068 return expression;
069 }
070 }