1 /*
2 * Copyright 2005 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 import org.w3c.dom.Node;
24
25 /**
26 * Helper class for using {@link QName}.
27 *
28 * @author Arjen Poutsma
29 * @see javax.xml.namespace.QName
30 * @since 1.0.0
31 */
32 public abstract class QNameUtils {
33
34 /** Indicates whether {@link QName} has a prefix. The first release of the class did not have this. */
35 private static boolean qNameHasPrefix;
36
37 static {
38 try {
39 QName.class.getDeclaredConstructor(new Class[]{String.class, String.class, String.class});
40 qNameHasPrefix = true;
41 }
42 catch (NoSuchMethodException e) {
43 qNameHasPrefix = false;
44 }
45 }
46
47 /**
48 * Creates a new <code>QName</code> with the given parameters. Sets the prefix if possible, i.e. if the
49 * <code>QName(String, String, String)</code> constructor can be found. If this constructor is not available (as is
50 * the case on older implementations of JAX-RPC), the prefix is ignored.
51 *
52 * @param namespaceUri namespace URI of the <code>QName</code>
53 * @param localPart local part of the <code>QName</code>
54 * @param prefix prefix of the <code>QName</code>. May be ignored.
55 * @return the created <code>QName</code>
56 * @see QName#QName(String,String,String)
57 */
58 public static QName createQName(String namespaceUri, String localPart, String prefix) {
59 if (qNameHasPrefix) {
60 return new QName(namespaceUri, localPart, prefix);
61 }
62 else {
63 return new QName(namespaceUri, localPart);
64 }
65 }
66
67 /**
68 * Returns the prefix of the given <code>QName</code>. Returns the prefix if available, i.e. if the
69 * <code>QName.getPrefix()</code> method can be found. If this method is not available (as is the case on older
70 * implementations of JAX-RPC), an empty string is returned.
71 *
72 * @param qName the <code>QName</code> to return the prefix from
73 * @return the prefix, if available, or an empty string
74 * @see javax.xml.namespace.QName#getPrefix()
75 */
76 public static String getPrefix(QName qName) {
77 return qNameHasPrefix ? qName.getPrefix() : "";
78 }
79
80 /**
81 * Validates the given String as a QName
82 *
83 * @param text the qualified name
84 * @return <code>true</code> if valid, <code>false</code> otherwise
85 */
86 public static boolean validateQName(String text) {
87 if (!StringUtils.hasLength(text)) {
88 return false;
89 }
90 if (text.charAt(0) == '{') {
91 int i = text.indexOf('}');
92
93 if (i == -1 || i == text.length() - 1) {
94 return false;
95 }
96 }
97 return true;
98 }
99
100 /**
101 * Returns the qualified name of the given DOM Node.
102 *
103 * @param node the node
104 * @return the qualified name of the node
105 */
106 public static QName getQNameForNode(Node node) {
107 if (node.getNamespaceURI() != null && node.getPrefix() != null && node.getLocalName() != null) {
108 return createQName(node.getNamespaceURI(), node.getLocalName(), node.getPrefix());
109 }
110 else if (node.getNamespaceURI() != null && node.getLocalName() != null) {
111 return new QName(node.getNamespaceURI(), node.getLocalName());
112 }
113 else if (node.getLocalName() != null) {
114 return new QName(node.getLocalName());
115 }
116 else {
117 // as a last resort, use the node name
118 return new QName(node.getNodeName());
119 }
120 }
121
122 /**
123 * Convert a <code>QName</code> to a qualified name, as used by DOM and SAX. The returned string has a format of
124 * <code>prefix:localName</code> if the prefix is set, or just <code>localName</code> if not.
125 *
126 * @param qName the <code>QName</code>
127 * @return the qualified name
128 */
129 public static String toQualifiedName(QName qName) {
130 String prefix = getPrefix(qName);
131 if (!StringUtils.hasLength(prefix)) {
132 return qName.getLocalPart();
133 }
134 else {
135 return prefix + ":" + qName.getLocalPart();
136 }
137 }
138
139 /**
140 * Convert a namespace URI and DOM or SAX qualified name to a <code>QName</code>. The qualified name can have the
141 * form <code>prefix:localname</code> or <code>localName</code>.
142 *
143 * @param namespaceUri the namespace URI
144 * @param qualifiedName the qualified name
145 * @return a QName
146 */
147 public static QName toQName(String namespaceUri, String qualifiedName) {
148 int idx = qualifiedName.indexOf(':');
149 if (idx == -1) {
150 return new QName(namespaceUri, qualifiedName);
151 }
152 else {
153 return createQName(namespaceUri, qualifiedName.substring(idx + 1), qualifiedName.substring(0, idx));
154 }
155 }
156
157 /**
158 * Parse the given qualified name string into a <code>QName</code>. Expects the syntax <code>localPart</code>,
159 * <code>{namespace}localPart</code>, or <code>{namespace}prefix:localPart</code>. This format resembles the
160 * <code>toString()</code> representation of <code>QName</code> itself, but allows for prefixes to be specified as
161 * well.
162 *
163 * @return a corresponding QName instance
164 * @throws IllegalArgumentException when the given string is <code>null</code> or empty.
165 */
166 public static QName parseQNameString(String qNameString) {
167 Assert.hasLength(qNameString, "QName text may not be null or empty");
168 if (qNameString.charAt(0) != '{') {
169 return new QName(qNameString);
170 }
171 else {
172 int endOfNamespaceURI = qNameString.indexOf('}');
173 if (endOfNamespaceURI == -1) {
174 throw new IllegalArgumentException(
175 "Cannot create QName from \"" + qNameString + "\", missing closing \"}\"");
176 }
177 int prefixSeperator = qNameString.indexOf(':', endOfNamespaceURI + 1);
178 String namespaceURI = qNameString.substring(1, endOfNamespaceURI);
179 if (prefixSeperator == -1) {
180 return new QName(namespaceURI, qNameString.substring(endOfNamespaceURI + 1));
181 }
182 else {
183 return createQName(namespaceURI, qNameString.substring(prefixSeperator + 1),
184 qNameString.substring(endOfNamespaceURI + 1, prefixSeperator));
185 }
186 }
187
188 }
189
190 }