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 /** 034 * A helper class for working with namespaces or creating namespace based expressions 035 * 036 * @version $Revision: 36321 $ 037 */ 038 public class Namespaces { 039 public static final String DEFAULT_NAMESPACE = "http://activemq.apache.org/camel/schema/spring"; 040 public static final String IN_NAMESPACE = "http://camel.apache.org/xml/in/"; 041 public static final String OUT_NAMESPACE = "http://camel.apache.org/xml/out/"; 042 public static final String SYSTEM_PROPERTIES_NAMESPACE = "http://camel.apache.org/xml/variables/system-properties"; 043 public static final String ENVIRONMENT_VARIABLES = "http://camel.apache.org/xml/variables/environment-variables"; 044 public static final String EXCHANGE_PROPERTY = "http://camel.apache.org/xml/variables/exchange-property"; 045 046 private Map<String, String> namespaces = new HashMap<String, String>(); 047 048 049 /** 050 * Creates a namespaces object from the given XML element 051 * 052 * @param element the XML element representing the XPath namespace context 053 */ 054 public Namespaces(Element element) { 055 add(element); 056 } 057 058 /** 059 * Creates a namespace context with a single prefix and URI 060 */ 061 public Namespaces(String prefix, String uri) { 062 add(prefix, uri); 063 } 064 065 /** 066 * Returns true if the given namespaceURI is empty or if it matches the 067 * given expected namespace 068 */ 069 public static boolean isMatchingNamespaceOrEmptyNamespace(String namespaceURI, String expectedNamespace) { 070 return ObjectHelper.isNullOrBlank(namespaceURI) || namespaceURI.equals(expectedNamespace); 071 } 072 public Namespaces add(String prefix, String uri) { 073 namespaces.put(prefix, uri); 074 return this; 075 } 076 077 public Namespaces add(Element element) { 078 // lets set the parent first in case we overload a prefix here 079 Node parentNode = element.getParentNode(); 080 if (parentNode instanceof org.w3c.dom.Element) { 081 add((Element) parentNode); 082 } 083 NamedNodeMap attributes = element.getAttributes(); 084 int size = attributes.getLength(); 085 for (int i = 0; i < size; i++) { 086 Attr node = (Attr) attributes.item(i); 087 String name = node.getName(); 088 if (name.startsWith("xmlns:")) { 089 String prefix = name.substring("xmlns:".length()); 090 String uri = node.getValue(); 091 add(prefix, uri); 092 } 093 } 094 return this; 095 } 096 097 /** 098 * Creates the XPath expression using the current namespace context 099 */ 100 public XPathExpression xpath(String expression) { 101 XPathExpression answer = new XPathExpression(expression); 102 configure(answer); 103 return answer; 104 } 105 106 /** 107 * Creates the XPath expression using the current namespace context 108 */ 109 public XPathExpression xpath(String expression, Class<?> resultType) { 110 XPathExpression answer = xpath(expression); 111 answer.setResultType(resultType); 112 return answer; 113 } 114 115 /** 116 * Creates the XQuery expression using the current namespace context 117 */ 118 public XQueryExpression xquery(String expression) { 119 XQueryExpression answer = new XQueryExpression(expression); 120 configure(answer); 121 return answer; 122 } 123 124 /** 125 * Creates the XQuery expression using the current namespace context 126 * and the given expected return type 127 */ 128 public XQueryExpression xquery(String expression, Class<?> resultType) { 129 XQueryExpression answer = new XQueryExpression(expression); 130 answer.setResultType(resultType); 131 configure(answer); 132 return answer; 133 } 134 135 public Map<String, String> getNamespaces() { 136 return namespaces; 137 } 138 139 140 /** 141 * Configures the namespace aware object 142 */ 143 public void configure(NamespaceAware namespaceAware) { 144 namespaceAware.setNamespaces(getNamespaces()); 145 146 } 147 }