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 org.w3c.dom.Attr; 023 import org.w3c.dom.Element; 024 import org.w3c.dom.NamedNodeMap; 025 import org.w3c.dom.Node; 026 027 import org.apache.camel.model.language.XPathExpression; 028 import org.apache.camel.model.language.XQueryExpression; 029 import org.apache.camel.spi.NamespaceAware; 030 import org.apache.camel.util.ObjectHelper; 031 032 /** 033 * A helper class for working with namespaces or creating namespace based expressions 034 * 035 * @version $Revision: 41910 $ 036 */ 037 public class Namespaces { 038 public static final String DEFAULT_NAMESPACE = "http://activemq.apache.org/camel/schema/spring"; 039 public static final String IN_NAMESPACE = "http://camel.apache.org/xml/in/"; 040 public static final String OUT_NAMESPACE = "http://camel.apache.org/xml/out/"; 041 public static final String SYSTEM_PROPERTIES_NAMESPACE = "http://camel.apache.org/xml/variables/system-properties"; 042 public static final String ENVIRONMENT_VARIABLES = "http://camel.apache.org/xml/variables/environment-variables"; 043 public static final String EXCHANGE_PROPERTY = "http://camel.apache.org/xml/variables/exchange-property"; 044 045 private Map<String, String> namespaces = new HashMap<String, String>(); 046 047 /** 048 * Creates a namespaces object from the given XML element 049 * 050 * @param element the XML element representing the XPath namespace context 051 */ 052 public Namespaces(Element element) { 053 add(element); 054 } 055 056 /** 057 * Creates a namespace context with a single prefix and URI 058 */ 059 public Namespaces(String prefix, String uri) { 060 add(prefix, uri); 061 } 062 063 /** 064 * Returns true if the given namespaceURI is empty or if it matches the 065 * given expected namespace 066 */ 067 public static boolean isMatchingNamespaceOrEmptyNamespace(String namespaceURI, String expectedNamespace) { 068 return ObjectHelper.isNullOrBlank(namespaceURI) || namespaceURI.equals(expectedNamespace); 069 } 070 071 public Namespaces add(String prefix, String uri) { 072 namespaces.put(prefix, uri); 073 return this; 074 } 075 076 public Namespaces add(Element element) { 077 // lets set the parent first in case we overload a prefix here 078 Node parentNode = element.getParentNode(); 079 if (parentNode instanceof org.w3c.dom.Element) { 080 add((Element) parentNode); 081 } 082 NamedNodeMap attributes = element.getAttributes(); 083 int size = attributes.getLength(); 084 for (int i = 0; i < size; i++) { 085 Attr node = (Attr) attributes.item(i); 086 String name = node.getName(); 087 if (name.startsWith("xmlns:")) { 088 String prefix = name.substring("xmlns:".length()); 089 String uri = node.getValue(); 090 add(prefix, uri); 091 } 092 } 093 return this; 094 } 095 096 /** 097 * Creates the XPath expression using the current namespace context 098 */ 099 public XPathExpression xpath(String expression) { 100 XPathExpression answer = new XPathExpression(expression); 101 configure(answer); 102 return answer; 103 } 104 105 /** 106 * Creates the XPath expression using the current namespace context 107 */ 108 public XPathExpression xpath(String expression, Class<?> resultType) { 109 XPathExpression answer = xpath(expression); 110 answer.setResultType(resultType); 111 return answer; 112 } 113 114 /** 115 * Creates the XQuery expression using the current namespace context 116 */ 117 public XQueryExpression xquery(String expression) { 118 XQueryExpression answer = new XQueryExpression(expression); 119 configure(answer); 120 return answer; 121 } 122 123 /** 124 * Creates the XQuery expression using the current namespace context 125 * and the given expected return type 126 */ 127 public XQueryExpression xquery(String expression, Class<?> resultType) { 128 XQueryExpression answer = new XQueryExpression(expression); 129 answer.setResultType(resultType); 130 configure(answer); 131 return answer; 132 } 133 134 public Map<String, String> getNamespaces() { 135 return namespaces; 136 } 137 138 /** 139 * Configures the namespace aware object 140 */ 141 public void configure(NamespaceAware namespaceAware) { 142 namespaceAware.setNamespaces(getNamespaces()); 143 144 } 145 }