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.RuntimeCamelException; 023 import org.apache.camel.util.ExchangeHelper; 024 import org.apache.commons.logging.Log; 025 import org.apache.commons.logging.LogFactory; 026 027 /** 028 * The processor which sends messages in a loop. 029 * 030 * @version $Revision: 52373 $ 031 */ 032 public class LoopProcessor extends DelegateProcessor { 033 public static final String PROP_ITER_COUNT = "CamelIterationCount"; 034 public static final String PROP_ITER_INDEX = "CamelIterationIndex"; 035 036 private static final Log LOG = LogFactory.getLog(LoopProcessor.class); 037 038 private Expression<Exchange> expression; 039 040 public LoopProcessor(Expression<Exchange> expression, Processor processor) { 041 super(processor); 042 this.expression = expression; 043 } 044 045 @Override 046 public void process(Exchange exchange) throws Exception { 047 // Intermediate conversion to String is needed when direct conversion to Integer is not available 048 // but evaluation result is a textual representation of a numeric value. 049 String text = ExchangeHelper.convertToType(exchange, String.class, expression.evaluate(exchange)); 050 Integer value = ExchangeHelper.convertToType(exchange, Integer.class, text); 051 if (value == null) { 052 // TODO: we should probably catch evaluate/convert exception an set is as fault (after fix for CAMEL-316) 053 throw new RuntimeCamelException("Expression \"" + expression + "\" does not evaluate to an int."); 054 } 055 int count = value.intValue(); 056 exchange.setProperty(PROP_ITER_COUNT, count); 057 for (int i = 0; i < count; i++) { 058 LOG.debug("LoopProcessor: iteration #" + i); 059 exchange.setProperty(PROP_ITER_INDEX, i); 060 super.process(exchange); 061 } 062 } 063 064 @Override 065 public String toString() { 066 return "Loop[for: " + expression + " times do: " + getProcessor() + "]"; 067 } 068 069 public Expression<Exchange> getExpression() { 070 return expression; 071 } 072 }