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.XmlRootElement; 020 021import org.apache.camel.Predicate; 022import org.apache.camel.model.language.ExpressionDefinition; 023import org.apache.camel.processor.FilterProcessor; 024import org.apache.camel.spi.Metadata; 025import org.apache.camel.spi.RouteContext; 026 027/** 028 * Triggers a route when an expression evaluates to <tt>true</tt> 029 * 030 * @version 031 */ 032@Metadata(label = "eip,routing") 033@XmlRootElement(name = "when") 034public class WhenDefinition extends ExpressionNode { 035 036 public WhenDefinition() { 037 } 038 039 public WhenDefinition(Predicate predicate) { 040 super(predicate); 041 } 042 043 public WhenDefinition(ExpressionDefinition expression) { 044 super(expression); 045 } 046 047 @Override 048 public String toString() { 049 return "When[" + description() + " -> " + getOutputs() + "]"; 050 } 051 052 protected String description() { 053 StringBuilder sb = new StringBuilder(); 054 if (getExpression() != null) { 055 String language = getExpression().getLanguage(); 056 if (language != null) { 057 sb.append(language).append("{"); 058 } 059 sb.append(getExpression().getLabel()); 060 if (language != null) { 061 sb.append("}"); 062 } 063 } 064 return sb.toString(); 065 } 066 067 @Override 068 public String getLabel() { 069 return "when[" + description() + "]"; 070 } 071 072 @Override 073 public FilterProcessor createProcessor(RouteContext routeContext) throws Exception { 074 return createFilterProcessor(routeContext); 075 } 076 077 /** 078 * Expression used as the predicate to evaluate whether this when should trigger and route the message or not. 079 */ 080 @Override 081 public void setExpression(ExpressionDefinition expression) { 082 // override to include javadoc what the expression is used for 083 super.setExpression(expression); 084 } 085 086 @Override 087 public ProcessorDefinition<?> endParent() { 088 // when using when in the DSL we don't want to end back to this when, but instead 089 // the parent of this, so return the parent 090 return this.getParent(); 091 } 092}