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    }