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 */ 017package org.apache.camel.model; 018 019import javax.xml.bind.annotation.XmlAccessType; 020import javax.xml.bind.annotation.XmlAccessorType; 021import javax.xml.bind.annotation.XmlAttribute; 022import javax.xml.bind.annotation.XmlRootElement; 023 024import org.apache.camel.Expression; 025import org.apache.camel.Processor; 026import org.apache.camel.model.language.ExpressionDefinition; 027import org.apache.camel.processor.LoopProcessor; 028import org.apache.camel.spi.Metadata; 029import org.apache.camel.spi.RouteContext; 030 031/** 032 * Processes a message multiple times 033 * 034 * @version 035 */ 036@Metadata(label = "eip,routing") 037@XmlRootElement(name = "loop") 038@XmlAccessorType(XmlAccessType.FIELD) 039public class LoopDefinition extends ExpressionNode { 040 041 @XmlAttribute 042 private Boolean copy; 043 044 public LoopDefinition() { 045 } 046 047 public LoopDefinition(Expression expression) { 048 super(expression); 049 } 050 051 public LoopDefinition(ExpressionDefinition expression) { 052 super(expression); 053 } 054 055 /** 056 * Enables copy mode so a copy of the input Exchange is used for each iteration. 057 * @return the builder 058 */ 059 public LoopDefinition copy() { 060 setCopy(true); 061 return this; 062 } 063 064 public Boolean getCopy() { 065 return copy; 066 } 067 068 /** 069 * If the copy attribute is true, a copy of the input Exchange is used for each iteration. 070 * That means each iteration will start from a copy of the same message. 071 * <p/> 072 * By default loop will loop the same exchange all over, so each iteration may 073 * have different message content. 074 */ 075 public void setCopy(Boolean copy) { 076 this.copy = copy; 077 } 078 079 @Override 080 public String toString() { 081 return "Loop[" + getExpression() + " -> " + getOutputs() + "]"; 082 } 083 084 @Override 085 public String getLabel() { 086 return "loop[" + getExpression() + "]"; 087 } 088 089 @Override 090 public Processor createProcessor(RouteContext routeContext) throws Exception { 091 Processor output = this.createChildProcessor(routeContext, true); 092 boolean isCopy = getCopy() != null && getCopy(); 093 return new LoopProcessor(output, getExpression().createExpression(routeContext), isCopy); 094 } 095 096 /** 097 * Expression to define how many times we should loop. Notice the expression is only evaluated once, and should return 098 * a number as how many times to loop. A value of zero or negative means no looping. The loop is like a for-loop fashion, 099 * if you want a while loop, then the dynamic router may be a better choice. 100 */ 101 @Override 102 public void setExpression(ExpressionDefinition expression) { 103 // override to include javadoc what the expression is used for 104 super.setExpression(expression); 105 } 106}