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.VtdXmlExpression;
028 import org.apache.camel.model.language.XPathExpression;
029 import org.apache.camel.model.language.XQueryExpression;
030 import org.apache.camel.spi.NamespaceAware;
031 import org.apache.camel.util.ObjectHelper;
032
033 /**
034 * A helper class for working with namespaces or creating namespace based expressions
035 *
036 * @version
037 */
038 public class Namespaces {
039 public static final String DEFAULT_NAMESPACE = "http://camel.apache.org/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 FUNCTION_NAMESPACE = "http://camel.apache.org/xml/function/";
043 public static final String SYSTEM_PROPERTIES_NAMESPACE = "http://camel.apache.org/xml/variables/system-properties";
044 public static final String ENVIRONMENT_VARIABLES = "http://camel.apache.org/xml/variables/environment-variables";
045 public static final String EXCHANGE_PROPERTY = "http://camel.apache.org/xml/variables/exchange-property";
046
047 private Map<String, String> namespaces = new HashMap<String, String>();
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.isEmpty(namespaceURI) || namespaceURI.equals(expectedNamespace);
071 }
072
073 public Namespaces add(String prefix, String uri) {
074 namespaces.put(prefix, uri);
075 return this;
076 }
077
078 public Namespaces add(Element element) {
079 // let's set the parent first in case we overload a prefix here
080 Node parentNode = element.getParentNode();
081 if (parentNode instanceof org.w3c.dom.Element) {
082 add((Element) parentNode);
083 }
084 NamedNodeMap attributes = element.getAttributes();
085 int size = attributes.getLength();
086 for (int i = 0; i < size; i++) {
087 Attr node = (Attr) attributes.item(i);
088 String name = node.getName();
089 if (name.startsWith("xmlns:")) {
090 String prefix = name.substring("xmlns:".length());
091 String uri = node.getValue();
092 add(prefix, uri);
093 }
094 }
095 return this;
096 }
097
098 /**
099 * Creates the XPath expression using the VTD-XML library using the current namespace context
100 */
101 public VtdXmlExpression vtdxml(String expression) {
102 VtdXmlExpression answer = new VtdXmlExpression(expression);
103 configure(answer);
104 return answer;
105 }
106
107 /**
108 * Creates the XPath expression using the current namespace context
109 */
110 public XPathExpression xpath(String expression) {
111 XPathExpression answer = new XPathExpression(expression);
112 configure(answer);
113 return answer;
114 }
115
116 /**
117 * Creates the XPath expression using the current namespace context
118 */
119 public XPathExpression xpath(String expression, Class<?> resultType) {
120 XPathExpression answer = xpath(expression);
121 answer.setResultType(resultType);
122 return answer;
123 }
124
125 /**
126 * Creates the XQuery expression using the current namespace context
127 */
128 public XQueryExpression xquery(String expression) {
129 XQueryExpression answer = new XQueryExpression(expression);
130 configure(answer);
131 return answer;
132 }
133
134 /**
135 * Creates the XQuery expression using the current namespace context
136 * and the given expected return type
137 */
138 public XQueryExpression xquery(String expression, Class<?> resultType) {
139 XQueryExpression answer = new XQueryExpression(expression);
140 answer.setResultType(resultType);
141 configure(answer);
142 return answer;
143 }
144
145 public Map<String, String> getNamespaces() {
146 return namespaces;
147 }
148
149 /**
150 * Configures the namespace aware object
151 */
152 public void configure(NamespaceAware namespaceAware) {
153 namespaceAware.setNamespaces(getNamespaces());
154 }
155 }