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.builder.xml; 018 019 import java.util.HashMap; 020 import java.util.Map; 021 022 import javax.xml.namespace.QName; 023 import javax.xml.xpath.XPathVariableResolver; 024 025 import org.apache.camel.Exchange; 026 import org.apache.camel.Message; 027 import org.apache.commons.logging.Log; 028 import org.apache.commons.logging.LogFactory; 029 030 import static org.apache.camel.builder.xml.Namespaces.ENVIRONMENT_VARIABLES; 031 import static org.apache.camel.builder.xml.Namespaces.EXCHANGE_PROPERTY; 032 import static org.apache.camel.builder.xml.Namespaces.IN_NAMESPACE; 033 import static org.apache.camel.builder.xml.Namespaces.OUT_NAMESPACE; 034 import static org.apache.camel.builder.xml.Namespaces.SYSTEM_PROPERTIES_NAMESPACE; 035 036 /** 037 * A variable resolver for XPath expressions which support properties on the 038 * messge, exchange as well as making system properties and environment 039 * properties available. 040 * 041 * @version $Revision: 51971 $ 042 */ 043 public class MessageVariableResolver implements XPathVariableResolver { 044 private static final transient Log LOG = LogFactory.getLog(MessageVariableResolver.class); 045 046 private Exchange exchange; 047 private Map<String, Object> variables = new HashMap<String, Object>(); 048 049 public Exchange getExchange() { 050 return exchange; 051 } 052 053 public void setExchange(Exchange exchange) { 054 this.exchange = exchange; 055 } 056 057 public Object resolveVariable(QName name) { 058 String uri = name.getNamespaceURI(); 059 String localPart = name.getLocalPart(); 060 Object answer = null; 061 062 Message in = exchange.getIn(); 063 if (uri == null || uri.length() == 0) { 064 answer = variables.get(localPart); 065 if (answer == null) { 066 Message message = in; 067 if (message != null) { 068 answer = message.getHeader(localPart); 069 } 070 if (answer == null) { 071 answer = exchange.getProperty(localPart); 072 } 073 } 074 } else if (uri.equals(SYSTEM_PROPERTIES_NAMESPACE)) { 075 try { 076 answer = System.getProperty(localPart); 077 } catch (Exception e) { 078 LOG.debug("Security exception evaluating system property: " + localPart 079 + ". Reason: " + e, e); 080 } 081 } else if (uri.equals(ENVIRONMENT_VARIABLES)) { 082 answer = System.getenv().get(localPart); 083 } else if (uri.equals(EXCHANGE_PROPERTY)) { 084 answer = exchange.getProperty(localPart); 085 } else if (uri.equals(IN_NAMESPACE)) { 086 answer = in.getHeader(localPart); 087 if (answer == null && localPart.equals("body")) { 088 answer = in.getBody(); 089 } 090 } else if (uri.equals(OUT_NAMESPACE)) { 091 Message out = exchange.getOut(false); 092 if (out != null) { 093 answer = out.getHeader(localPart); 094 if (answer == null && localPart.equals("body")) { 095 answer = out.getBody(); 096 } 097 } 098 } 099 100 // If we can't find an answer we must return void. 101 // We can't return null then the xpath engine will throw a NullPointerException 102 if (answer == null) { 103 return Void.class; 104 } else { 105 return answer; 106 } 107 } 108 109 public void addVariable(String localPart, Object value) { 110 variables.put(localPart, value); 111 } 112 }