1 /*
2 * Copyright 2005-2010 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.springframework.xml.namespace;
18
19 import javax.xml.namespace.QName;
20
21 import org.springframework.util.Assert;
22 import org.springframework.util.StringUtils;
23
24 import org.w3c.dom.Node;
25
26 /**
27 * Helper class for using {@link QName}.
28 *
29 * @author Arjen Poutsma
30 * @see javax.xml.namespace.QName
31 * @since 1.0.0
32 */
33 public abstract class QNameUtils {
34
35 /** Indicates whether {@link QName} has a prefix. The first release of the class did not have this. */
36 private static boolean qNameHasPrefix;
37
38 static {
39 try {
40 QName.class.getDeclaredConstructor(new Class[]{String.class, String.class, String.class});
41 qNameHasPrefix = true;
42 }
43 catch (NoSuchMethodException e) {
44 qNameHasPrefix = false;
45 }
46 }
47
48 /**
49 * Creates a new <code>QName</code> with the given parameters. Sets the prefix if possible, i.e. if the
50 * <code>QName(String, String, String)</code> constructor can be found. If this constructor is not available (as is
51 * the case on older implementations of JAX-RPC), the prefix is ignored.
52 *
53 * @param namespaceUri namespace URI of the <code>QName</code>
54 * @param localPart local part of the <code>QName</code>
55 * @param prefix prefix of the <code>QName</code>. May be ignored.
56 * @return the created <code>QName</code>
57 * @see QName#QName(String,String,String)
58 */
59 public static QName createQName(String namespaceUri, String localPart, String prefix) {
60 if (qNameHasPrefix) {
61 return new QName(namespaceUri, localPart, prefix);
62 }
63 else {
64 return new QName(namespaceUri, localPart);
65 }
66 }
67
68 /**
69 * Returns the prefix of the given <code>QName</code>. Returns the prefix if available, i.e. if the
70 * <code>QName.getPrefix()</code> method can be found. If this method is not available (as is the case on older
71 * implementations of JAX-RPC), an empty string is returned.
72 *
73 * @param qName the <code>QName</code> to return the prefix from
74 * @return the prefix, if available, or an empty string
75 * @see javax.xml.namespace.QName#getPrefix()
76 */
77 public static String getPrefix(QName qName) {
78 return qNameHasPrefix ? qName.getPrefix() : "";
79 }
80
81 /**
82 * Validates the given String as a QName
83 *
84 * @param text the qualified name
85 * @return <code>true</code> if valid, <code>false</code> otherwise
86 */
87 public static boolean validateQName(String text) {
88 if (!StringUtils.hasLength(text)) {
89 return false;
90 }
91 if (text.charAt(0) == '{') {
92 int i = text.indexOf('}');
93
94 if (i == -1 || i == text.length() - 1) {
95 return false;
96 }
97 }
98 return true;
99 }
100
101 /**
102 * Returns the qualified name of the given DOM Node.
103 *
104 * @param node the node
105 * @return the qualified name of the node
106 */
107 public static QName getQNameForNode(Node node) {
108 if (node.getNamespaceURI() != null && node.getPrefix() != null && node.getLocalName() != null) {
109 return createQName(node.getNamespaceURI(), node.getLocalName(), node.getPrefix());
110 }
111 else if (node.getNamespaceURI() != null && node.getLocalName() != null) {
112 return new QName(node.getNamespaceURI(), node.getLocalName());
113 }
114 else if (node.getLocalName() != null) {
115 return new QName(node.getLocalName());
116 }
117 else {
118 // as a last resort, use the node name
119 return new QName(node.getNodeName());
120 }
121 }
122
123 /**
124 * Convert a <code>QName</code> to a qualified name, as used by DOM and SAX. The returned string has a format of
125 * <code>prefix:localName</code> if the prefix is set, or just <code>localName</code> if not.
126 *
127 * @param qName the <code>QName</code>
128 * @return the qualified name
129 */
130 public static String toQualifiedName(QName qName) {
131 String prefix = getPrefix(qName);
132 if (!StringUtils.hasLength(prefix)) {
133 return qName.getLocalPart();
134 }
135 else {
136 return prefix + ":" + qName.getLocalPart();
137 }
138 }
139
140 /**
141 * Convert a namespace URI and DOM or SAX qualified name to a <code>QName</code>. The qualified name can have the
142 * form <code>prefix:localname</code> or <code>localName</code>.
143 *
144 * @param namespaceUri the namespace URI
145 * @param qualifiedName the qualified name
146 * @return a QName
147 */
148 public static QName toQName(String namespaceUri, String qualifiedName) {
149 int idx = qualifiedName.indexOf(':');
150 if (idx == -1) {
151 return new QName(namespaceUri, qualifiedName);
152 }
153 else {
154 return createQName(namespaceUri, qualifiedName.substring(idx + 1), qualifiedName.substring(0, idx));
155 }
156 }
157
158 /**
159 * Parse the given qualified name string into a <code>QName</code>. Expects the syntax <code>localPart</code>,
160 * <code>{namespace}localPart</code>, or <code>{namespace}prefix:localPart</code>. This format resembles the
161 * <code>toString()</code> representation of <code>QName</code> itself, but allows for prefixes to be specified as
162 * well.
163 *
164 * @return a corresponding QName instance
165 * @throws IllegalArgumentException when the given string is <code>null</code> or empty.
166 */
167 public static QName parseQNameString(String qNameString) {
168 Assert.hasLength(qNameString, "QName text may not be null or empty");
169 if (qNameString.charAt(0) != '{') {
170 return new QName(qNameString);
171 }
172 else {
173 int endOfNamespaceURI = qNameString.indexOf('}');
174 if (endOfNamespaceURI == -1) {
175 throw new IllegalArgumentException(
176 "Cannot create QName from \"" + qNameString + "\", missing closing \"}\"");
177 }
178 int prefixSeperator = qNameString.indexOf(':', endOfNamespaceURI + 1);
179 String namespaceURI = qNameString.substring(1, endOfNamespaceURI);
180 if (prefixSeperator == -1) {
181 return new QName(namespaceURI, qNameString.substring(endOfNamespaceURI + 1));
182 }
183 else {
184 return createQName(namespaceURI, qNameString.substring(prefixSeperator + 1),
185 qNameString.substring(endOfNamespaceURI + 1, prefixSeperator));
186 }
187 }
188
189 }
190
191 }